139 results on '"STIRAP"'
Search Results
2. Adiabatically Manipulated Systems Interacting with Spin Baths beyond the Rotating Wave Approximation
- Author
-
Benedetto Militello and Anna Napoli
- Subjects
STIRAP ,spin bath ,Rotating Wave Approximation ,Physics ,QC1-999 - Abstract
The Stimulated Raman Adiabatic Passage (STIRAP) on a three-state system interacting with a spin bath is considered, focusing on the efficiency of the population transfer. Our analysis is based on the perturbation treatment of the interaction term evaluated beyond the Rotating Wave Approximation, thus focusing on the limit of weak system–bath coupling. The analytical expression of the correction to the efficiency and the consequent numerical analysis show that, in most of the cases, the effects of the environment are negligible, confirming the robustness of the population transfer.
- Published
- 2024
- Full Text
- View/download PDF
3. Investigation of Population Transfer in the Two Coupled Λ-Type Three-Level Systems Based on Stimulated Raman Adiabatic Passage
- Author
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Ali Hatami, Mehdi Hosseini, and Fatemeh Ahmadinouri
- Subjects
population transfer ,stirap ,coupled systems ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Applied optics. Photonics ,TA1501-1820 - Abstract
Abstract Efficient and coherent transfer of population between different quantum states. In this study, we delve into the investigation of population transfer in two coupled Λ-type three-level systems using the STIRAP technique. Our research focuses on understanding the dynamics and control of population transfer within these systems. The system Hamiltonian is constructed based on the physical condition of the coupled structure, then the respective time-dependent Schrodinger equation is solved numerically. By analyzing the adiabatic conditions, we explore the interaction between the two coupled Λ-type systems examine the role of various parameters, such as the time of the peak amplitude, and determine the pulse width. Furthermore, we observe the impact of interaction on the transition probability, comparing coupled systems to uncoupled systems. The findings of this study shed light on the underlying mechanisms of STIRAP and contribute to the development of advanced quantum control techniques.
- Published
- 2024
- Full Text
- View/download PDF
4. Adiabatic Manipulation of a System Interacting with a Spin Bath.
- Author
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Militello, Benedetto and Napoli, Anna
- Subjects
- *
POPULATION transfers , *ADIABATIC flow , *MOTION , *HARMONIC oscillators - Abstract
The Stimulated Raman Adiabatic Passage, a very efficient technique for manipulating a quantum system based on the adiabatic theorem, is analyzed in the case where the manipulated physical system is interacting with a spin bath. The exploitation of the rotating wave approximation allows for the identification of a constant of motion, which simplifies both the analytical and the numerical treatment, which allows for evaluating the total unitary evolution of the system and bath. The efficiency of the population transfer process is investigated in several regimes, including the weak and strong coupling with the environment and the off-resonance. The formation of appropriate Zeno subspaces explains the lowering of the efficiency in the strong damping regime. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Efficient production of ultracold polar molecules 23Na40K in their absolute ground state via intermediate state of the coupled complex B1Π|ν = 4〉 ∼ c3Σ+ |ν = 25〉.
- Author
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Li, Zi-Liang, Gu, Zheng-Yu, Wang, Peng-Jun, and Zhang, Jing
- Abstract
We report on the efficient creation of a sample of 2.2×10
4 fermionic polar molecules23 Na40 K in their rovibrational ground state X1 Σ+ |ν = 0, J = 0〉 at 247 nK via an intermediate state of the spin-orbit coupled complex B1 Π |ν = 4〉 ∼ c3 Σ+ |ν = 25〉. Compared with the intermediate state of the coupled complex B1 Π |ν = 12〉 ∼ c3 Π+ |ν = 35〉, this intermediate state has the larger Franck-Condon factors for up- and down-leg coupling of stimulated Raman adiabatic passage (STIRAP). We demonstrate this two-photon pathway to the23 Na40 K ground state molecules and find that the one-way STIRAP transfer efficiency reaches 75%. The molecules23 Na40 K in their rovibrational ground state are an ideal candidate for the quantum simulation and quantum information of ultracold molecules with long-range interaction. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
6. Electronic Structure, Spectroscopy, Cold Ion–Atom Elastic Collision Properties, and Photoassociation Formation Prediction of the (MgCs) + Molecular Ion.
- Author
-
Farjallah, Mohamed, Sardar, Dibyendu, Deb, Bimalendu, and Berriche, Hamid
- Subjects
ION-atom collisions ,IONS ,ELASTICITY ,ELECTRONIC structure ,ELASTIC scattering ,POTENTIAL energy - Abstract
In this paper, we extensively study the electronic structure, interactions, and dynamics of the (MgCs)
+ molecular ion. The exchanges between the alkaline atom and the low-energy cationic alkaline earths, which are important in the field of cold and ultracold quantum chemistry, are studied. We use an ab initio approach based on the formalism of non-empirical pseudo-potential for Mg2+ and Cs+ cores, large Gaussian basis sets, and full-valence configuration interaction. In this context, the (MgCs)+ cation is treated as an effective two-electron system. Adiabatic potential energy curves and their spectroscopic constants for the ground and the first 20 excited states of1,3 Σ+ symmetries are determined. Furthermore, we identify the avoided crossings between the electronic states of1,3 Σ+ symmetries. These crossings are related to the charge transfer process between the two ionic limits, Mg/Cs+ and Mg+ /Cs. Therefore, vibrational-level spacings and the transition and permanent dipole moments are presented and analyzed. Using the produced potential energy data, the ground-state scattering wave functions and elastic cross-sections are calculated for a wide range of energies. In addition, we predict the formation of a translationally and rotationally cold molecular ion (MgCs)+ in the ground-state electronic potential energy through a stimulated Raman-type process aided by ion–atom cold collision. In the low-energy limit (<1 mK), elastic scattering cross-sections exhibit Wigner law threshold behavior, while in the high-energy limit, the cross-sections act as a function of energy E go as E−1/3 . A qualitative discussion about the possibilities of forming cold (MgCs)+ molecular ions by photoassociative spectroscopy is presented. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
7. Adiabatic Manipulation of a System Interacting with a Spin Bath
- Author
-
Benedetto Militello and Anna Napoli
- Subjects
STIRAP ,spin bath ,quantum Zeno effect ,Mathematics ,QA1-939 - Abstract
The Stimulated Raman Adiabatic Passage, a very efficient technique for manipulating a quantum system based on the adiabatic theorem, is analyzed in the case where the manipulated physical system is interacting with a spin bath. The exploitation of the rotating wave approximation allows for the identification of a constant of motion, which simplifies both the analytical and the numerical treatment, which allows for evaluating the total unitary evolution of the system and bath. The efficiency of the population transfer process is investigated in several regimes, including the weak and strong coupling with the environment and the off-resonance. The formation of appropriate Zeno subspaces explains the lowering of the efficiency in the strong damping regime.
- Published
- 2023
- Full Text
- View/download PDF
8. Perfect stimulated Raman adiabatic passage with imperfect finite-time pulses.
- Author
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Dogra, Shruti and Paraoanu, Gheorghe Sorin
- Subjects
- *
MOVEMENT sequences - Abstract
We present a well-tailored sequence of two Gaussian-pulsed drives that achieves perfect population transfer in stimulated Raman adiabatic passage. We give a theoretical analysis of the optimal truncation and relative placement of the Stokes and pump pulses. Further, we obtain the power and the duration of the protocol for a given pulse width. Importantly, the duration of the protocol required to attain a desired value of fidelity depends only logarithmically on the infidelity. Subject to optimal truncation of the drives and with reference to the point of fastest transfer, we obtain a new adiabaticity criteria, which is remarkably simple and effective. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
9. Stimulated Raman adiabatic passage in a quantum system near a plasmonic nanoparticle.
- Author
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Domenikou, Natalia, Thanopulos, Ioannis, Stefanatos, Dionisis, Yannopapas, Vassilios, and Paspalakis, Emmanuel
- Subjects
- *
BRILLOUIN scattering , *DENSITY matrices , *PLASMONICS , *SEMICONDUCTOR quantum dots , *EXCITED states , *DECAY rates (Radioactivity) - Abstract
We investigate theoretically the population transfer process in a Λ-type three-level quantum system (QS) near a metallic nanosphere using the stimulated Raman adiabatic passage (STIRAP) technique. We combine density matrix quantum dynamical calculations with first-principle electromagnetic calculations, which quantify the influence of the plasmonic nanoparticle on the electric field of the pump and Stokes pulses in STIRAP as well as on the spontaneous emission rates within the Λ-type system. We study the population transfer process by varying the free-space spontaneous emission rate, the distance of the QS from the nanosphere, the polarization direction with respect to the nanoparticle surface and the relative strength of the pump and Stokes pulses used in STIRAP. We find that when the pump and Stokes fields have tangential and radial polarizations with respect to the nanosphere surface, the transfer efficiency is improved due to the increase of the decay rate of the excited state to the target state relatively to the decay to the initial state. The optimal population transfer is achieved for small interparticle distances, moderate free space spontaneous decay rate, large values of the pump Rabi frequency and small values of the Stokes Rabi frequency. When we exchange the polarization directions of the pump and Stokes fields we can still find a range of parameters where the population transfer remains efficient, but larger Stokes Rabi frequencies are necessary to overcome the increased decay rate from the excited state back to the initial state. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
10. Robust and Broadband Graphene Surface Plasmon Waveguide Coupler via Quantum Control
- Author
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Yun Chen, Wei Huang, Kelvin J. A. Ooi, and Wentao Zhang
- Subjects
graphene ,surface plasmon polaritons ,STIRAP ,quantum control ,waveguide coupler ,Physics ,QC1-999 - Abstract
In this article, a novel graphene subwavelength waveguide coupler is designed based on the quantum control theory. Compared with metal surface plasmon polaritons (SPPs), graphene surface plasmon polaritons (GSPPs) have a smaller SPP wavelength and tunable properties. The dielectric load graphene plasmon waveguide (DLGPW) is used for designing to avoid the influence of the edge shape of the graphene nanoribbons on the waveguide mode. The coupling coefficient between the waveguides is calculated by using the coupled-mode theory (CMT). Due to the subwavelength properties of the graphene surface plasmons (GSP) and the robustness of the quantum control technique, our device is more compact and robust against perturbations of geometrical parameters under the premise of high transmission efficiency. The device we designed also has broadband characteristics, ranging from 30 THz to 40 THz, with high transmission efficiency when considering the transmission loss. We believe that our device will significantly contribute to integrated optics and photo-communication.
- Published
- 2022
- Full Text
- View/download PDF
11. Efficient production of ultracold polar molecules 23Na40K in their absolute ground state via intermediate state of the coupled complex B1Π|ν = 4〉 ∼ c3Σ+ |ν = 25〉
- Author
-
Li, Zi-Liang, Gu, Zheng-Yu, Wang, Peng-Jun, and Zhang, Jing
- Published
- 2023
- Full Text
- View/download PDF
12. Optimal shape of STIRAP pulses for large dissipation at the intermediate level.
- Author
-
Stefanatos, Dionisis and Paspalakis, Emmanuel
- Subjects
- *
COMPUTER simulation - Abstract
We study the problem of maximizing population transfer efficiency in the STIRAP system for the case where the dissipation rate of the intermediate state is much higher than the maximum amplitude of the control fields. Under this assumption, the original three-level system can be reduced to a couple of equations involving the initial and target states only. We find the control fields which maximize the population transfer to the target state for a given duration T, without using any penalty involving the population of the lossy intermediate state, but under the constraint that the sum of the intensities of the pump and Stokes pulses is constant, so the total field has constant amplitude and the only control parameter is the mixing angle of the two fields. In the optimal solution the mixing angle changes in the bang-singular-bang manner, where the initial and final bangs correspond to equal instantaneous rotations, while the intermediate singular arc to a linear change with time. We show that the optimal angle of the initial and final rotations is the unique solution of a transcendental equation where duration T appears as a parameter, while the optimal slope of the intermediate linear change as well as the optimal transfer efficiency is expressed as functions of this optimal angle. The corresponding optimal solution recovers the counterintuitive pulse-sequence, with nonzero pump and Stokes fields at the boundaries. We also show with numerical simulations that transfer efficiency values close to the optimal derived using the approximate system can also be obtained with the original STIRAP system using dissipation rates comparable to the maximum control amplitude. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
13. Efficient pathway to NaCs ground state molecules
- Author
-
Claire Warner, Niccolò Bigagli, Aden Z Lam, Weijun Yuan, Siwei Zhang, Ian Stevenson, and Sebastian Will
- Subjects
ultracold molecules ,ground state molecules ,STIRAP ,molecular spectroscopy ,Science ,Physics ,QC1-999 - Abstract
We present a study of two-photon pathways for the transfer of NaCs molecules to their rovibrational ground state. Starting from NaCs Feshbach molecules, we perform bound-bound excited state spectroscopy in the wavelength range from 900 nm to 940 nm, covering more than 30 vibrational states of the $c \, ^3\Sigma^+$ , $b \, ^3\Pi$ , and $B \, ^1\Pi$ electronic states. Analyzing the rotational substructure, we identify the highly mixed $c \, ^3\Sigma^+_1 \ \vert v = 22\rangle \sim b \, ^3\Pi_1 \ \vert v = 54\rangle$ state as an efficient bridge for stimulated Raman adiabatic passage. We demonstrate transfer into the NaCs ground state with an efficiency of up to 88(4)%. Highly efficient transfer is critical for the realization of many-body quantum phases of strongly dipolar NaCs molecules and high fidelity detection of single molecules, for example, in spin physics experiments in optical lattices and quantum information experiments in optical tweezer arrays.
- Published
- 2023
- Full Text
- View/download PDF
14. Spin coherent quantum transport of electrons between defects in diamond
- Author
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Oberg Lachlan M., Huang Eric, Reddy Prithvi M., Alkauskas Audrius, Greentree Andrew D., Cole Jared H., Manson Neil B., Meriles Carlos A., and Doherty Marcus W.
- Subjects
diamond ,stirap ,quantum transport ,Physics ,QC1-999 - Abstract
The nitrogen-vacancy (NV) color center in diamond has rapidly emerged as an important solid-state system for quantum information processing. Whereas individual spin registers have been used to implement small-scale diamond quantum computing, the realization of a large-scale device requires the development of an on-chip quantum bus for transporting information between distant qubits. Here, we propose a method for coherent quantum transport of an electron and its spin state between distant NV centers. Transport is achieved by the implementation of spatial stimulated adiabatic Raman passage through the optical control of the NV center charge states and the confined conduction states of a diamond nanostructure. Our models show that, for two NV centers in a diamond nanowire, high-fidelity transport can be achieved over distances of order hundreds of nanometers in timescales of order hundreds of nanoseconds. Spatial adiabatic passage is therefore a promising option for realizing an on-chip spin quantum bus.
- Published
- 2019
- Full Text
- View/download PDF
15. Effective Full Population Transfer in M-System Using Scanning Technique.
- Author
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Aleksanyan, A. Yu.
- Abstract
In this work, a theoretical model of the full population transfer in a five-level M type system is demonstrated. The method is based on the technique of linear scanning of the frequency of the laser field close to the resonance frequency of the corresponding transition. A comparison of the full population transfer obtained with the chirping technique with the results obtained by the method, which is based on the adiabatic population transfer of atomic levels, is made. The results are obtained using numerical computations. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
16. Fractional population transfer among three-level systems in a cavity by Stark-shift-chirped rapid adiabatic passage.
- Author
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Shirkhanghah, N., Saadati-Niari, M., and Ahadpour, S.
- Subjects
- *
LASER beams , *LASER pulses , *INHOMOGENEOUS materials , *COHERENCE (Physics) , *Q-switched lasers - Abstract
We show that the technique of Stark-chirped rapid adiabatic passage (SCRAP), hitherto used for complete population transfer among three states in atoms and molecules, offers a simple and robust method for creating coherent superpositions of states in the interaction of a three-level atom with cavity and laser fields. We also use this technique to generate maximally atom–photon entangled states. SCRAP in three-level systems uses three laser pulses: a strong far-off-resonant pulse modifies the transition frequencies by inducing dynamic Stark shifts and thereby creating time-dependent level crossings among the three diabatic states, while near-resonant and moderately strong pump and Stokes pulses, appropriately offset in time, drive the population between the initial and final states via adiabatic passage. In our method, the atom falls through a high-Q cavity and encounters the cavity mode and the laser beams such that the populations are transferred fractionally between two ground states (f-SCRAP). The populations of the created superposition are controlled by the detunings of the pump and cavity fields from the transition frequencies. Unlike the technique of fractional stimulated Raman adiabatic passage (f-STIRAP), f-SCRAP can be applied to one-photon as well as multiphoton transitions and it is a powerful alternative tool for f-STIRAP in the media exhibiting inhomogeneous broadening. This technique is robust against moderate variations in peak Rabi frequencies, in distance between the center of the cavity and axis of the pump and Stark laser beams and in the velocity of the atom. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
17. Robustness of STIRAP Shortcuts under Ornstein-Uhlenbeck Noise in the Energy Levels.
- Author
-
Stefanatos, Dionisis, Blekos, Kostas, and Paspalakis, Emmanuel
- Subjects
NOISE ,POLYNOMIAL time algorithms ,TECHNOLOGICAL innovations ,COMPUTER simulation - Abstract
In this article, we evaluate the efficiency of two shortcuts to adiabaticity for the STIRAP system, in the presence of Ornstein–Uhlenbeck noise in the energy levels. The shortcuts under consideration preserve the interactions of the original Hamiltonian, without adding extra counterdiabatic terms, which directly connect the initial and target states. The first shortcut is such that the mixing angle is a polynomial function of time, while the second shortcut is derived from Gaussian pulses. Extensive numerical simulations indicate that both shortcuts perform quite well and robustly even in the presence of relatively large noise amplitudes, while their performance is decreased with increasing noise correlation time. For similar pulse amplitudes and durations, the efficiency of classical STIRAP is highly degraded even in the absence of noise. When using pulses with similar areas for the two STIRAP shortcuts, the shortcut derived from Gaussian pulses appears to be more efficient. Since STIRAP is an essential tool for the implementation of emerging quantum technologies, the present work is expected to find application in this broad research field. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
18. Superadiabatic STIRAP: Population Transfer and Quantum Rotation Gates
- Author
-
Issoufa, Youssouf Hamidou, Messikh, Azeddine, Diniz Junqueira Barbosa, Simone, Series editor, Chen, Phoebe, Series editor, Du, Xiaoyong, Series editor, Filipe, Joaquim, Series editor, Kara, Orhun, Series editor, Kotenko, Igor, Series editor, Liu, Ting, Series editor, Sivalingam, Krishna M., Series editor, Washio, Takashi, Series editor, Gong, Maoguo, editor, Pan, Linqiang, editor, Song, Tao, editor, and Zhang, Gexiang, editor
- Published
- 2016
- Full Text
- View/download PDF
19. Coherent Raman Control and On-Chip Integration of the Nitrogen-Vacancy Center in Diamond
- Author
-
Schröder, Tim, Benson, Oliver, Budker, Dmitry, Böhm, Florian Maximilian, Schröder, Tim, Benson, Oliver, Budker, Dmitry, and Böhm, Florian Maximilian
- Abstract
Die im Rahmen dieser Arbeit durchgeführten Experimente befassen sich mit zwei Aspekten des Stickstoff-Fehlstellen-Zentrum (engl.: nitrogen-vacancy center, NV-Zentrum) in Diamant, einem der bekanntesten Quantenspin-Defekte und vielversprechendem Festkörpersystem für künftige Anwendungen in der Quantentechnologie, wie z. B. Quantensensorik und Quanteninformation im Nanomaßstab. Zum einen werden neue Mikrowellen-Raman-Spin-Manipulationsverfahren an dem NV-Elektronenspin untersucht, und zum anderen wird eine neuartige On-Chip-Plattform für Quantenanwendungen und die hybride Integration dieser Plattform mit einem einzelnen NV-Zentrum vorgestellt. Es wird über die kohärente Mikrowellen-Raman-Kontrolle an den Elektronenspin des NV-Zentrums berichtet, die den Dipol-verbotenen Übergang zwischen zwei Spin-Subniveaus im elektronischen Triplett-Grundzustand des NV-Zentrums direkt treiben kann. Folglich wurden die stimulierten Raman-Übergänge (engl.: stimulated Raman transitions, SRT) und die stimulierte adiabatische Raman-Passage (engl.: stimulated Raman adiabatic passage, STIRAP) theoretisch und numerisch analysiert und erfolgreich an einem einzelnen NV-Zentrum experimentell verifiziert und umgesetzt. Weiterhin wird die deterministische Integration eines einzelnen NV-Zentrums mit einer photonischen Plattform behandelt. Diese extra für diesen Zweck entwickelte photonische Plattform besteht dabei ausschließlich aus thermisch auf einem Silizium Substrat gewachsenem Siliziumdioxid und zeichnet sich dabei durch ihre ultraniedrige Fluoreszenz aus. Experimentell wurde die Integration eines vorselektierten NV-Emitters mit einem Rasterkraftmikroskop durchgeführt und die On-Chip-Anregung des Quantenemitters sowie die Kopplung von Einzelphotonen an die geführte Mode der integrierten Struktur nachgewiesen. Dieser Ansatz zeigt das Potenzial dieser Plattform als robuste nanoskalige Schnittstelle von photonischen On-Chip-Strukturen mit einzelnen Festkörper-Qubits., This thesis revolves around the nitrogen-vacancy (NV) defect center in diamond, one of the best-known quantum spin defects and a promising solid-state system for future applications in quantum technology, such as nanoscale quantum sensing and quantum information. Since the manipulation of the NV center's electron spin is crucial for many applications, the development of new or the adaption of known spin manipulation schemes to the NV center spin is crucial to expand the application prospects of the NV center. Thus, this work reports on the adaption of coherent microwave Raman control to the electron spin of the NV center, which can drive the dipole-forbidden transition between two spin sublevels in the NV center's triplet electronic ground state. Consequently, the stimulated Raman transitions (SRT) and stimulated Raman adiabatic passage (STIRAP) two-photon microwave Raman processes were theoretically and numerically analyzed and successfully implemented and verified experimentally on a single NV center electron spin. The two Raman schemes were then also compared in terms of their robustness and success of the spin swap. Apart from this, scalable on-chip coupling of single photon emitters and quantum memories with single optical modes is crucial for building future fully integrated nanophotonic devices. Thus, a purpose-built photonic platform consisting entirely of silicon dioxide thermally grown on a silicon substrate, which stands out by its ultra-low fluorescence, was developed. Experimentally, the integration of a preselected NV emitter was performed with an atomic force microscope, and on-chip excitation of the quantum emitter as well as coupling of single photons to the guided mode of the integrated structure could be demonstrated. This approach demonstrates the potential of this platform as a robust nanoscale interface of on-chip photonic structures with single solid-state qubits.
- Published
- 2023
20. Coherent Raman Control and On-Chip Integration of the Nitrogen-Vacancy Center in Diamond
- Author
-
Böhm, Florian Maximilian, Schröder, Tim, Benson, Oliver, and Budker, Dmitry
- Subjects
Stickstoff-Fehlstelle ,Integrierte Schaltung ,SRT ,Einzelphoton ,Physik ,Photonik ,NV ,Rasterkraftmikroskop ,ddc:530 ,Spin Manipulation ,Integrated Circuit ,Atomic Force Microscope ,Raman ,Confocal Microscope ,Physics ,PIC ,Konfokalmikroskop ,Optics ,Nano ,Spinmanipulation ,530 Physik ,Quantum Optics ,Nitrogen-Vacancy ,Farbzentrum ,Optik ,Nanomanipulation ,Photonics ,STIRAP ,AFM ,Color Center ,Single Photon ,Quantenoptik - Abstract
Die im Rahmen dieser Arbeit durchgeführten Experimente befassen sich mit zwei Aspekten des Stickstoff-Fehlstellen-Zentrum (engl.: nitrogen-vacancy center, NV-Zentrum) in Diamant, einem der bekanntesten Quantenspin-Defekte und vielversprechendem Festkörpersystem für künftige Anwendungen in der Quantentechnologie, wie z. B. Quantensensorik und Quanteninformation im Nanomaßstab. Zum einen werden neue Mikrowellen-Raman-Spin-Manipulationsverfahren an dem NV-Elektronenspin untersucht, und zum anderen wird eine neuartige On-Chip-Plattform für Quantenanwendungen und die hybride Integration dieser Plattform mit einem einzelnen NV-Zentrum vorgestellt. Es wird über die kohärente Mikrowellen-Raman-Kontrolle an den Elektronenspin des NV-Zentrums berichtet, die den Dipol-verbotenen Übergang zwischen zwei Spin-Subniveaus im elektronischen Triplett-Grundzustand des NV-Zentrums direkt treiben kann. Folglich wurden die stimulierten Raman-Übergänge (engl.: stimulated Raman transitions, SRT) und die stimulierte adiabatische Raman-Passage (engl.: stimulated Raman adiabatic passage, STIRAP) theoretisch und numerisch analysiert und erfolgreich an einem einzelnen NV-Zentrum experimentell verifiziert und umgesetzt. Weiterhin wird die deterministische Integration eines einzelnen NV-Zentrums mit einer photonischen Plattform behandelt. Diese extra für diesen Zweck entwickelte photonische Plattform besteht dabei ausschließlich aus thermisch auf einem Silizium Substrat gewachsenem Siliziumdioxid und zeichnet sich dabei durch ihre ultraniedrige Fluoreszenz aus. Experimentell wurde die Integration eines vorselektierten NV-Emitters mit einem Rasterkraftmikroskop durchgeführt und die On-Chip-Anregung des Quantenemitters sowie die Kopplung von Einzelphotonen an die geführte Mode der integrierten Struktur nachgewiesen. Dieser Ansatz zeigt das Potenzial dieser Plattform als robuste nanoskalige Schnittstelle von photonischen On-Chip-Strukturen mit einzelnen Festkörper-Qubits. This thesis revolves around the nitrogen-vacancy (NV) defect center in diamond, one of the best-known quantum spin defects and a promising solid-state system for future applications in quantum technology, such as nanoscale quantum sensing and quantum information. Since the manipulation of the NV center's electron spin is crucial for many applications, the development of new or the adaption of known spin manipulation schemes to the NV center spin is crucial to expand the application prospects of the NV center. Thus, this work reports on the adaption of coherent microwave Raman control to the electron spin of the NV center, which can drive the dipole-forbidden transition between two spin sublevels in the NV center's triplet electronic ground state. Consequently, the stimulated Raman transitions (SRT) and stimulated Raman adiabatic passage (STIRAP) two-photon microwave Raman processes were theoretically and numerically analyzed and successfully implemented and verified experimentally on a single NV center electron spin. The two Raman schemes were then also compared in terms of their robustness and success of the spin swap. Apart from this, scalable on-chip coupling of single photon emitters and quantum memories with single optical modes is crucial for building future fully integrated nanophotonic devices. Thus, a purpose-built photonic platform consisting entirely of silicon dioxide thermally grown on a silicon substrate, which stands out by its ultra-low fluorescence, was developed. Experimentally, the integration of a preselected NV emitter was performed with an atomic force microscope, and on-chip excitation of the quantum emitter as well as coupling of single photons to the guided mode of the integrated structure could be demonstrated. This approach demonstrates the potential of this platform as a robust nanoscale interface of on-chip photonic structures with single solid-state qubits.
- Published
- 2023
21. High-fidelity formation of deeply bound ultracold molecules via non-Hermitian shortcut to adiabaticity
- Author
-
Jia-Hui Zhang and Fu-Quan Dou
- Subjects
deeply bound ultracold molecules ,STIRAP ,non-Hermitian shortcut to adiabaticity ,spontaneous emission ,Science ,Physics ,QC1-999 - Abstract
Stimulated Raman adiabatic passage allows robust transfer between two ends of a three-state quantum system and has been employed to transfer weakly bound Feshbach molecules into their deeply bound rovibrational ground state. However, the efficient transfer remains to be explored. Here we propose a possible alternative route, based on a recently developed non-Hermitian shortcut to adiabaticity method. It is able to realize single-step transfer efficiencies up to 100% even in the presence of a decaying excited level, surpassing all the previous methods. We also prove that our scheme is robust against the external field parameter fluctuations and is expected to be applicable for abundant molecular species.
- Published
- 2021
- Full Text
- View/download PDF
22. Ultracold 88Sr2 molecules in the absolute ground state
- Author
-
K H Leung, E Tiberi, B Iritani, I Majewska, R Moszynski, and T Zelevinsky
- Subjects
ultracold molecules ,strontium ,molecular spectroscopy ,magic wavelength ,photoassociation ,STIRAP ,Science ,Physics ,QC1-999 - Abstract
We report efficient all-optical creation of an ultracold gas of alkaline-earth-metal dimers, ^88 Sr _2 , in their absolute ground state. Starting with weakly bound singlet molecules formed by narrow-line photoassociation in an optical lattice, followed by stimulated Raman adiabatic passage (STIRAP) via a singlet-dominant channel in the $(1){0}_{u}^{+}$ excited potential, we prepare pure samples of more than 5500 molecules in ${X}^{1}{{\Sigma}}_{g}^{+}(v=0,\enspace J=0)$ . We observe two-body collisional loss rates close to the universal limit for both the least bound and most bound vibrational states in ${X}^{1}{{\Sigma}}_{g}^{+}$ . We demonstrate the enhancement of STIRAP efficiency in a magic-wavelength optical lattice where thermal decoherence is eliminated. Our results pave the way for the use of alkaline-earth-metal dimers for high-precision spectroscopy, and indicate favorable prospects for robust quantum state preparation of ultracold molecules involving closed-shell atoms, as well as molecule assembly in deep optical traps tuned to a magic wavelength.
- Published
- 2021
- Full Text
- View/download PDF
23. Robustness of STIRAP Shortcuts under Ornstein-Uhlenbeck Noise in the Energy Levels
- Author
-
Dionisis Stefanatos, Kostas Blekos, and Emmanuel Paspalakis
- Subjects
stirap ,shortcuts to adiabaticity ,dephasing ,ornstein–uhlenbeck noise ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In this article, we evaluate the efficiency of two shortcuts to adiabaticity for the STIRAP system, in the presence of Ornstein−Uhlenbeck noise in the energy levels. The shortcuts under consideration preserve the interactions of the original Hamiltonian, without adding extra counterdiabatic terms, which directly connect the initial and target states. The first shortcut is such that the mixing angle is a polynomial function of time, while the second shortcut is derived from Gaussian pulses. Extensive numerical simulations indicate that both shortcuts perform quite well and robustly even in the presence of relatively large noise amplitudes, while their performance is decreased with increasing noise correlation time. For similar pulse amplitudes and durations, the efficiency of classical STIRAP is highly degraded even in the absence of noise. When using pulses with similar areas for the two STIRAP shortcuts, the shortcut derived from Gaussian pulses appears to be more efficient. Since STIRAP is an essential tool for the implementation of emerging quantum technologies, the present work is expected to find application in this broad research field.
- Published
- 2020
- Full Text
- View/download PDF
24. Optomechanical cooling by STIRAP-assisted energy transfer: an alternative route towards the mechanical ground state
- Author
-
Bijita Sarma, Thomas Busch, and Jason Twamley
- Subjects
cavity optomechanics ,mechanical cooling ,STIRAP ,Science ,Physics ,QC1-999 - Abstract
Standard optomechanical cooling methods ideally require weak coupling and cavity damping rates which enable the motional sidebands to be well resolved. If the coupling is too large then sideband-resolved cooling is unstable or the rotating wave approximation can become invalid. In this work we describe a protocol to cool a mechanical resonator coupled to a driven optical mode in an optomechanical cavity, which is also coupled to an optical mode in another auxiliary optical cavity, and both the cavities are frequency-modulated. We show that by modulating the amplitude of the drive as well, one can execute a type of STIRAP transfer of occupation from the mechanical mode to the lossy auxiliary optical mode which results in cooling of the mechanical mode. We show how this protocol can outperform normal optomechanical sideband cooling in various regimes such as the strong coupling and the unresolved sideband limit.
- Published
- 2020
- Full Text
- View/download PDF
25. Theoretical Study on Spin-Selective Coherent Electron Transfer in a Quantum Dot Array
- Author
-
Shumpei Masuda, Kuan Yen Tan, and Mikio Nakahara
- Subjects
spin-selective electron transfer ,stirap ,shortcuts to adiabaticity ,Elementary particle physics ,QC793-793.5 - Abstract
Recently, we proposed the spin-selective coherent electron transfer in a silicon-quantum-dot array. It requires temporal tuning of two pulses of an oscillating magnetic field and gate voltage control. This paper proposes a simpler method that requires a single pulse of oscillating magnetic field and gate voltage control. We examined the robustness of the control against the error in the pulse amplitude and the effect of the excited states relaxation to the control efficiency. In addition, we propose a novel control method based on a shortcuts-to-adiabaticity protocol, which utilizes two pulses but requires temporal control of the pulse amplitude for only one of them. We compared their efficiencies under the effect of realistic pulse amplitude errors and relaxation.
- Published
- 2019
- Full Text
- View/download PDF
26. Spectroscopic properties of the molecular ions BeX+ (X=Na, K, Rb): forming cold molecular ions from an ion-atom mixture by stimulated Raman adiabatic process.
- Author
-
Ladjimi, Hela, Sardar, Dibyendu, Farjallah, Mohamed, Alharzali, Nisrin, Naskar, Somnath, Mlika, Rym, Berriche, Hamid, and Deb, Bimalendu
- Subjects
- *
ION-atom collisions , *RAMAN scattering , *ADIABATIC processes , *QUANTUM chemistry , *ION analysis - Abstract
In this theoretical work, we calculate potential energy curves, spectroscopic parameters and transition dipole moments of molecular ions BeX+ (X=Na, K, Rb) composed of alkaline ion Be and alkali atom X with a quantum chemistry approach based on the pseudopotential model, Gaussian basis sets, effective core polarisation potentials and full configuration interaction. We study in detail collisions of the alkaline ion and alkali atom in quantum regime. Besides, we study the possibility of the formation of molecular ions from the ion-atom colliding systems by stimulated Raman adiabatic process and discuss the parameters regime under which the population transfer is feasible. Our results are important for ion-atom cold collisions and experimental realisation of cold molecular ion formation. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
27. Liouvillian of the Open STIRAP Problem.
- Author
-
Mathisen, Thomas and Larson, Jonas
- Subjects
- *
ADIABATIC flow , *QUANTUM mechanics , *ENERGY dissipation , *FREEZING , *ADIABATIC processes - Abstract
With the corresponding Liouvillian as a starting point, we demonstrate two seemingly new phenomena of the STIRAP problem when subjected to irreversible losses. It is argued that both of these can be understood from an underlying Zeno effect, and in particular both can be viewed as if the environment assists the STIRAP population transfer. The first of these is found for relative strong dephasing, and, in the language of the Liouvillian, it is explained from the explicit form of the matrix generating the time-evolution; the coherence terms of the state decay off, which prohibits further population transfer. For pure dissipation, another Zeno effect is found, where the presence of a non-zero Liouvillian gap protects the system's (adiabatic) state from non-adiabatic excitations. In contrast to full Zeno freezing of the evolution, which is often found in many problems without explicit time-dependence, here, the freezing takes place in the adiabatic basis such that the system still evolves but adiabatically. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
28. Creation of N -partite W-states by adiabatic passage and pulse area techniques.
- Author
-
Mirza-Zadeh, S., Saadati-Niari, M., and Amniat-Talab, M.
- Subjects
- *
ROBUST control , *PHOTON emission , *GROUND state (Quantum mechanics) , *ADIABATIC flow , *QUANTUM optics - Abstract
We propose two relatively robust schemes to effectively generate controllableN-partite W states in atom-cavity-laser systems. In these schemes, we consider a situation where a traveling atom initially in the ground state, interacts simultaneously with the cavity-mode and the laser fields through stimulated Raman adiabatic passage and pulse area techniques in optical cavities. Losses due to atomic spontaneous emission are efficiently suppressed by employing appropriately designed atom-field couplings and suitable pulse ordering. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
29. Generation of Photon Pairs in the Light-Matter Ultrastrong Coupling Regime: From Casimir Radiation to Stimulated Raman Adiabatic Passage
- Author
-
Alessandro Ridolfo
- Subjects
ultrastrong light-matter coupling ,STIRAP ,superconducting qubits ,General Works - Abstract
The ultrastrong coupling regime of light-matter interaction is achieved when the coupling strength is a significant fraction of the natural frequencies of the noninteracting parts. Physics in this regime has recently attracted great interest, both theoretically and experimentally being a fruitful platform to test fundamental quantum mechanics in a new non-perturbative regime, and for applications to quantum technologies.Here we discuss the generation of photon-pair states, which is a distinctive feature of this new regime, and interesting new dynamicsl effects both in optomechanics and in circuit-QED architectures.
- Published
- 2019
- Full Text
- View/download PDF
30. A pathway to ultracold bosonic 23Na39K ground state molecules
- Author
-
Kai K Voges, Philipp Gersema, Torsten Hartmann, Torben A Schulze, Alessandro Zenesini, and Silke Ospelkaus
- Subjects
STIRAP ,molecular spectroscopy ,ultracold polar molecules ,bosonic quantum gases ,Science ,Physics ,QC1-999 - Abstract
We spectroscopically investigate a pathway for the conversion of ^23 Na ^39 K Feshbach molecules into rovibronic ground state molecules via stimulated Raman adiabatic passage. Using photoassociation spectroscopy from the diatomic scattering threshold in the a ^3 Σ ^+ potential, we locate the resonantly mixed electronically excited intermediate states $| {B}^{1}{\rm{\Pi }},v=8\rangle $ and $| {c}^{3}{{\rm{\Sigma }}}^{+},v=30\rangle $ which, due to their singlet–triplet admixture, serve as an ideal bridge between predominantly a ^3 Σ ^+ Feshbach molecules and pure X ^1 Σ ^+ ground state molecules. We investigate their hyperfine structure and present a simple model to determine the singlet–triplet coupling of these states. Using Autler–Townes spectroscopy, we locate the rovibronic ground state of the ^23 Na ^39 K molecule ( $| {X}^{1}{{\rm{\Sigma }}}^{+},v=0,N=0\rangle $ ) and the second rotationally excited state N = 2 to unambiguously identify the ground state. We also extract the effective transition dipole moment from the excited to the ground state. Our investigations result in a fully characterized scheme for the creation of ultracold bosonic ^23 Na ^39 K ground state molecules.
- Published
- 2019
- Full Text
- View/download PDF
31. Perfect stimulated Raman adiabatic passage with imperfect finite-time pulses
- Author
-
Shruti Dogra, Gheorghe Sorin Paraoanu, Superconducting Qubits and Circuit QED, Centre of Excellence in Quantum Technology, QTF, Department of Applied Physics, Aalto-yliopisto, and Aalto University
- Subjects
Quantum Physics ,superconducting qubits ,FOS: Physical sciences ,STIRAP ,Quantum Physics (quant-ph) ,optimally truncated finite-time pulses ,Condensed Matter Physics ,adiabaticity criteria ,Atomic and Molecular Physics, and Optics - Abstract
We present a well-tailored sequence of two Gaussian-pulsed drives that achieves perfect population transfer in STImulated Raman Adiabatic Passage (STIRAP). We give a theoretical analysis of the optimal truncation and relative placement of the Stokes and pump pulses. Further, we obtain the power and the duration of the protocol for a given pulse width. Importantly, the duration of the protocol required to attain a desired value of fidelity depends only logarithmically on the infidelity. Subject to optimal truncation of the drives and with reference to the point of fastest transfer, we obtain a new adiabaticity criteria, which is remarkably simple and effective., 7 pages, 7 figures
- Published
- 2022
32. Advances in quantum control of three-level superconducting circuit architectures.
- Author
-
Falci, G., Di Stefano, P. G., Ridolfo, A., D'Arrigo, A., Paraoanu, G. S., and Paladino, E.
- Subjects
- *
SUPERCONDUCTING circuits , *QUANTUM states , *SOLID state physics , *QUANTUM optics , *MICROWAVES , *QUANTUM electrodynamics - Abstract
Advanced control in Lambda (Λ) scheme of a solid state architecture of artificial atoms and quantized modes would allow the translation to the solid-state realm of a whole class of phenomena from quantum optics, thus exploiting new physics emerging in larger integrated quantum networks and for stronger couplings. However control solid-state devices has constraints coming from selection rules, due to symmetries which on the other hand yield protection from decoherence, and from design issues, for instance that coupling to microwave cavities is not directly switchable. We present two new schemes for the Λ-STIRAP control problem with the constraint of one or two classical driving fields being always-on. We show how these protocols are converted to apply to circuit-QED architectures. We finally illustrate an application to coherent spectroscopy of the so called ultrastrong atom-cavity coupling regime. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
33. IMPROVED ATOM INTERFEROMETER PERFORMANCE USING COUNTERINTUITIVE STIMULATED RAMAN ADIABATIC PASSAGE
- Author
-
Narducci, Francesco A., Lee, Jeffrey G., Physics (PH), Tatasciore, Branden, Narducci, Francesco A., Lee, Jeffrey G., Physics (PH), and Tatasciore, Branden
- Abstract
Atom interferometers depend on light/matter interactions and are extremely sensitive sensors capable of being employed as accelerometers, rotation sensors, and gravity and magnetic gradiometers. Typical interferometers use a well-known velocity (generally from atoms launched out of an atomic trap) to interferometrically measure quantities of interest (e.g., acceleration and rotation). This thesis evaluates the effects of atom velocity in an atom interferometer sensor that exists at NPS, which uses a continuous beam of cold rubidium atoms with a narrow but not monochromatic range of velocities passing through continuous laser fields. The atom’s velocity dictates the interaction time between the atom and laser. However, this combination results in pulse errors due to velocity averaging. One method to counteract these pulse errors uses the so-called counterintuitive laser arrangement—a method known as stimulated Raman adiabatic passage (STIRAP). STIRAP will be shown to be a more robust approach. Starting with the atoms in one of the ground states, all or a portion of the atoms can be transferred to the other ground state in a well-controlled manner. Changes in acceleration and rotation can be sensed with very high precision by a detection laser resulting in applicability as a highly sensitive accelerometer or gyroscope. This project explores experimentally and theoretically the utility of counterintuitive pulse sequences for atom interferometry applications., http://archive.org/details/improvedatominte1094566730, Outstanding Thesis, Lieutenant, United States Navy, Approved for public release. distribution is unlimited
- Published
- 2021
34. Optomechanical cooling by STIRAP-assisted energy transfer: an alternative route towards the mechanical ground state
- Author
-
Bijita, Sarma, Thomas, Busch, Jason, Twamley, Bijita, Sarma, Thomas, Busch, and Jason, Twamley
- Abstract
Standard optomechanical cooling methods ideally require weak coupling and cavity damping rates which enable the motional sidebands to be well resolved. If the coupling is too large then sideband-resolved cooling is unstable or the rotating wave approximation can become invalid. In this work we describe a protocol to cool a mechanical resonator coupled to a driven optical mode in an optomechanical cavity, which is also coupled to an optical mode in another auxiliary optical cavity, and both the cavities are frequency-modulated. We show that by modulating the amplitude of the drive as well, one can execute a type of STIRAP transfer of occupation from the mechanical mode to the lossy auxiliary optical mode which results in cooling of the mechanical mode. We show how this protocol can outperform normal optomechanical sideband cooling in various regimes such as the strong coupling and the unresolved sideband limit., source:https://iopscience.iop.org/article/10.1088/1367-2630/abbf24
- Published
- 2021
35. Stimulated Raman adiabatic passage with two-color x-ray pulses
- Subjects
XFEL ,Quantum control ,STIRAP - Published
- 2021
36. Excitation of Rydberg states of atoms by adiabatic transfer of populations.
- Author
-
Gazazyan, E., Grigoryan, G., and Chaltykyan, V.
- Abstract
We introduce the adiabatic interaction of five-level ladder-type system with four laser pulses provided that all three two-photon detunings are equal to zero. The analytical expressions for a quasi-energy of the system under consideration and the adiabatic condition of interaction are derived. The process of effective adiabatic excitation of such a system that can be successfully applied to obtain the Rydberg atoms is analysed. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
37. Collective effects in subwavelength hybrid systems: a numerical analysis.
- Author
-
Sukharev, Maxim and Malinovskaya, Svetlana A.
- Subjects
- *
WAVELENGTHS , *NUMERICAL analysis , *QUANTUM theory , *NONLINEAR theories , *LIOUVILLE'S theorem , *ELECTROMAGNETIC fields - Abstract
Optical properties of ensembles of coupled three-level quantum emitters are investigated in linear and non-linear regimes. The model of the Maxwell–Liouville von Neumann equations is implemented to explore the reflection, transmission, and absorption of a thin layer of atom-like emitters at low and high densities. The stimulated Raman adiabatic passage is analysed in systems of coupled quantum emitters of various densities. It is shown that coupling via local electromagnetic fields shifts the energy levels and modifies propagating fields leading to a mixed final population distribution and appearance of new absorption resonances. Strong femtosecond pulses induce population inversion in emitters leading to optical gain. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
38. An ultracold gas of bosonic 23Na39K ground-state molecules
- Author
-
Voges, Kai Konrad and Voges, Kai Konrad
- Abstract
Ultracold bialkali polar molecules play a leading part at the frontline of quantum physics. They recently attract a lot of attention in the field of ultracold quantum chemistry, quantum many-body physics and quantum simulations. The key for their success is the rich internal level structure with rotational and vibrational degrees of freedom and their large electric dipole moments. Still, only a handful of molecular species are available at ultracold temperatures until now, although it is highly desirable to produce new molecular species to further expand the range of applications. Besides direct laser cooling methods for molecules, the assembly of heteronuclear ground-state molecules from ultracold atomic mixtures is the most promising approach for the creation of polar molecules. It includes the formation of weakly bound Feshbach molecules from the diatomic mixture and the subsequent two-photon stimulated Raman adiabatic passage (STIRAP) transfer to the rovibrational ground state. This creation strategy has been successfully demonstrated for the first time in the pioneering experiments at JILA with ultracold 40K87Rb molecules. Since then, only a few more molecular species from different alkali atoms have been created, namely 6Li23Na, 23Na40K, 23Na87Rb and 87Rb133Cs. In this thesis, I report the successful creation of a new species of ultracold polar ground-state molecules: 23Na39K. Starting from an ultracold mixture of bosonic 23Na and 39K atoms, weakly bound molecules are created. For this purpose, a Feshbach resonance in a high angular momentum scattering channel is chosen, experimentally identified and characterized. Close to this resonance the weakly bound Feshbach molecules are formed using resonant radio frequency radiation. For the two-photon ground-state transfer, a unique, highly specialized two-color laser system is designed and realized. It is used for one- and two-photon spectroscopy to identify the relevant transitions for the ground-state transfer. Based
- Published
- 2020
39. Adiabatic Population Transfer Based on a Double Stimulated Raman Adiabatic Passage.
- Author
-
Akram, Muhammad and Saif, Farhan
- Subjects
- *
LASER research , *ELECTROMAGNETIC pulses , *QUANTUM states , *BLOCH equations , *LASERS - Abstract
Stimulated Raman adiabatic passage (STIRAP) is an adiabatic population-transfer technique that uses two coherent laser pulses in counter-intuitive order, namely, pump and stoke, to achieve complete transfer between two quantum states. Here, we propose a double STIRAP scheme whereby the electronic levels of a four-level atom are coupled by three laser fields forming two pairs of stoke and pump pulses. We derive the optical Bloch equations through the master equation for studying the population dynamics. We show that manipulating the time between two STIRAP sequences provides the state transfer near unity. In particular, we show that there occurs a certain maximum transfer efficiency that can be achieved in the double STIRAP process. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
40. A Tutorial on Optimal Control and Reinforcement Learning methods for Quantum Technologies
- Author
-
Luigi Giannelli, Pierpaolo Sgroi, Jonathon Brown, Gheorghe Sorin Paraoanu, Mauro Paternostro, Elisabetta Paladino, Giuseppe Falci, University of Catania, Queen's University Belfast, Centre of Excellence in Quantum Technology, QTF, Department of Applied Physics, Aalto-yliopisto, and Aalto University
- Subjects
Computer Science::Machine Learning ,Quantum Physics ,Quantum technologies ,ComputerSystemsOrganization_MISCELLANEOUS ,Machine learning ,Reinforcement learning ,General Physics and Astronomy ,FOS: Physical sciences ,Quantum control ,STIRAP ,Quantum Physics (quant-ph) ,Optimal control - Abstract
Quantum Optimal Control is an established field of research which is necessary for the development of Quantum Technologies. In recent years, Machine Learning techniques have been proved usefull to tackle a variety of quantum problems. In particular, Reinforcement Learning has been employed to address typical problems of control of quantum systems. In this tutorial we introduce the methods of Quantum Optimal Control and Reinforcement Learning by applying them to the problem of three-level population transfer. The jupyter notebooks to reproduce some of our results are open-sourced and available on github., Comment: 15 pages, 11 figures
- Published
- 2021
- Full Text
- View/download PDF
41. Stimulated Raman adiabatic passage with two-color x-ray pulses
- Author
-
Stephen H. Southworth, Antonio Picón, and Jordi Mompart
- Subjects
Physics ,Free electron model ,Astrophysics::High Energy Astrophysical Phenomena ,XFEL ,Stimulated Raman adiabatic passage ,General Physics and Astronomy ,chemistry.chemical_element ,Quantum control ,Laser ,law.invention ,Neon ,chemistry ,Coherent control ,law ,Excited state ,Femtosecond ,STIRAP ,Atomic physics ,Coherence (physics) - Abstract
Recent techniques in x-ray free electron lasers allow the generation of highly coherent, intense x-ray pulses with time lengths on the order of femtoseconds. Here we explore the possibilities of using such x-ray pulses to control matter based on coherence. In particular we propose a theoretical scheme to perform stimulated Raman adiabatic passage in the x-ray regime by using inner-hole excited states. Numerical results in two well-known systems, the neon atom and the carbon monoxide molecule, show a robust control of population transfer. In the molecule, vibrational selectivity is achieved with femtosecond x-ray pulses. This work supports the possibility of using two-color x-ray pulses for coherent control.
- Published
- 2021
42. PRODUCTION OF A QUANTUM GAS OF ROVIBRONIC GROUND-STATE MOLECULES IN AN OPTICAL LATTICE.
- Author
-
DANZL, JOHANN G., MARK, MANFRED J., HALLER, ELMAR, GUSTAVSSON, MATTIAS, HART, RUSSELL, and NÄGERL, HANNS-CHRISTOPH
- Subjects
QUANTUM gases ,GROUND state (Quantum mechanics) ,OPTICAL lattices ,BOSE-Einstein condensation ,ULTRACOLD molecules - Published
- 2010
43. POPULATION TRANSFER PROCESSES: FROM ATOMS TO CLUSTERS AND BOSE-EINSTEIN CONDENSATE.
- Author
-
NESTERENKO, V. O., CRUZ, F. F. DE SOUZA, LAPOLLI, E. L., and REINHARD, P.-G.
- Subjects
BOSE-Einstein condensation ,ATOMIC interactions ,RAMAN scattering ,QUANTUM optics ,LINEAR systems - Published
- 2008
44. A tutorial on optimal control and reinforcement learning methods for quantum technologies.
- Author
-
Giannelli, Luigi, Sgroi, Pierpaolo, Brown, Jonathon, Paraoanu, Gheorghe Sorin, Paternostro, Mauro, Paladino, Elisabetta, and Falci, Giuseppe
- Subjects
- *
MACHINE learning , *REINFORCEMENT learning - Abstract
• Reinforcement Learning and Optimal Control for control of quantum systems. • Formalization of the problem is very important for good results. • An easily generalizable code is available on github. Quantum Optimal Control is an established field of research which is necessary for the development of Quantum Technologies. In recent years, Machine Learning techniques have been proved useful to tackle a variety of quantum problems. In particular, Reinforcement Learning has been employed to address typical problems of control of quantum systems. In this tutorial we introduce the methods of Quantum Optimal Control and Reinforcement Learning by applying them to the problem of three-level population transfer. The jupyter notebooks to reproduce some of our results are open-sourced and available on github 1. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. Detection of motional ground state population of a trapped ion using delayed pulses
- Author
-
F Gebert, Y Wan, F Wolf, Jan C Heip, and Piet O Schmidt
- Subjects
adiabatic state manipulation ,STIRAP ,trapped ions ,motional state population ,03.75.Be ,32.80.Qk ,Science ,Physics ,QC1-999 - Abstract
Efficient preparation and detection of the motional state of trapped ions is important in many experiments ranging from quantum computation to precision spectroscopy. We investigate the stimulated Raman adiabatic passage (STIRAP) technique for the manipulation of motional states in a trapped ion system. The presented technique uses a Raman coupling between two hyperfine ground states in ^25 Mg ^+ , implemented with delayed pulses, which removes a single phonon independent of the initial motional state. We show that for a thermal probability distribution of motional states the STIRAP population transfer is more efficient than a stimulated Raman Rabi pulse on a motional sideband. In contrast to previous implementations, a large detuning of more than 200 times the natural linewidth of the transition is used. This approach renders STIRAP suitable for atoms in which resonant laser fields would populate nearby fluorescing excited states and thus impede the STIRAP process. We use the technique to measure the wavefunction overlap of excited motional states with the motional ground state. This is an important application for force sensing applications using trapped ions, such as photon recoil spectroscopy, in which the signal is proportional to the depletion of motional ground state population. Furthermore, a determination of the ground state population enables a simple measurement of the ion's temperature.
- Published
- 2016
- Full Text
- View/download PDF
46. Multistate APLIP and VibLIP: from molecular bond extension to atomic transport.
- Author
-
Suominen, Kalle-Antti
- Subjects
- *
CHEMICAL bonds , *ATOM transfer reactions , *POTENTIAL energy surfaces , *NUCLEAR vibrational states , *PHYSICAL sciences - Abstract
APLIP is a method for using a STIRAP-like three-state configuration with two laser pulses for continuous extension of a molecular bond, introduced in 1998. It is based on time-dependent light-induced potential surfaces (LIP). In VibLIP one extends the idea into a method for tailoring the vibrational state while changing the electronic state, introduced in 2000. Here I discuss the extension of both methods to situations that involve more than three electronic states, and note the possibility of using the method on adiabatic transport of atoms between microtraps or equivalent structures. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
47. Preparation of W state among spatially separated atomic ensembles collectively controlled by a single atom via adiabatic passage.
- Author
-
Zhang, Chun-Ling, Li, Wen-Zhang, and Chen, Mei-Feng
- Subjects
- *
ATOM lasers , *COMPUTER simulation , *QUANTUM teleportation , *QUBITS , *OPTICAL fibers , *RAMAN spectroscopy - Abstract
Abstract: We propose a way to prepare W state among atomic ensembles via stimulated Raman adiabatic passage (STIRAP) technique. The atomic ensembles are trapped in spatially separated cavities collectively linked to another cavity trapping a single atom by optical fibers. Our strictly numerical simulations show that, the atomic spontaneous emission, the cavity decay and the fiber loss are efficiently suppressed by the engineering adiabatic passage. The method can be generalized to prepare W state among any number of atomic ensembles. We believe that our proposal will promote development of quantum teleportation, especially quantum state engineering of multi-target-qubit collectively controlled by a qubit. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
48. Optomechanical cooling by STIRAP-assisted energy transfer $:$ an alternative route towards the mechanical ground state
- Author
-
Bijita Sarma, Jason Twamley, and Thomas Busch
- Subjects
Work (thermodynamics) ,General Physics and Astronomy ,FOS: Physical sciences ,Physics::Optics ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Resonator ,law ,0103 physical sciences ,010306 general physics ,Coupling ,Physics ,Quantum Physics ,Sideband ,business.industry ,cavity optomechanics ,Amplitude ,Optical cavity ,mechanical cooling ,Optoelectronics ,Rotating wave approximation ,Physics::Accelerator Physics ,STIRAP ,Ground state ,business ,Quantum Physics (quant-ph) ,Optics (physics.optics) ,Physics - Optics - Abstract
Standard optomechanical cooling methods ideally require weak coupling and cavity damping rates which enable the motional sidebands to be well resolved. If the coupling is too large then sideband-resolved cooling is unstable or the rotating wave approximation can become invalid. In this work we describe a protocol to cool a mechanical resonator coupled to a driven optical mode in an optomechanical cavity, which is also coupled to an optical mode in another auxiliary optical cavity, and both the cavities are frequency-modulated. We show that by modulating the amplitude of the drive as well, one can execute a type of STIRAP transfer of occupation from the mechanical mode to the lossy auxiliary optical mode which results in cooling of the mechanical mode. We show how this protocol can outperform normal optomechanical sideband cooling in various regimes such as the strong coupling and the unresolved sideband limit.
- Published
- 2020
49. Robustness of STIRAP Shortcuts under Ornstein-Uhlenbeck Noise in the Energy Levels
- Author
-
Emmanuel Paspalakis, Kostas Blekos, and Dionisis Stefanatos
- Subjects
Dephasing ,Gaussian ,01 natural sciences ,lcsh:Technology ,010305 fluids & plasmas ,lcsh:Chemistry ,symbols.namesake ,shortcuts to adiabaticity ,Robustness (computer science) ,0103 physical sciences ,General Materials Science ,Statistical physics ,010306 general physics ,Instrumentation ,lcsh:QH301-705.5 ,Fluid Flow and Transfer Processes ,Physics ,lcsh:T ,Process Chemistry and Technology ,General Engineering ,Ornstein–Uhlenbeck process ,Noise correlation ,stirap ,dephasing ,ornstein–uhlenbeck noise ,lcsh:QC1-999 ,Computer Science Applications ,Quantum technology ,Amplitude ,lcsh:Biology (General) ,lcsh:QD1-999 ,lcsh:TA1-2040 ,symbols ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:Physics - Abstract
In this article, we evaluate the efficiency of two shortcuts to adiabaticity for the STIRAP system, in the presence of Ornstein&ndash, Uhlenbeck noise in the energy levels. The shortcuts under consideration preserve the interactions of the original Hamiltonian, without adding extra counterdiabatic terms, which directly connect the initial and target states. The first shortcut is such that the mixing angle is a polynomial function of time, while the second shortcut is derived from Gaussian pulses. Extensive numerical simulations indicate that both shortcuts perform quite well and robustly even in the presence of relatively large noise amplitudes, while their performance is decreased with increasing noise correlation time. For similar pulse amplitudes and durations, the efficiency of classical STIRAP is highly degraded even in the absence of noise. When using pulses with similar areas for the two STIRAP shortcuts, the shortcut derived from Gaussian pulses appears to be more efficient. Since STIRAP is an essential tool for the implementation of emerging quantum technologies, the present work is expected to find application in this broad research field.
- Published
- 2020
50. Ultracold Gas of Bosonic (NaK)-Na-23-K-39 Ground-State Molecules
- Author
-
Voges, Kai K., Gersema, Philipp, Borgloh, Mara Meyer zum Alten, Schulze, Torben A., Hartmann, Torsten, Zenesini, Alessandro, and Ospelkaus, Silke
- Subjects
Condensed Matter::Quantum Gases ,Ultracold Molecules ,Physics::Atomic and Molecular Clusters ,Physics::Atomic Physics ,Physics::Chemical Physics ,NaK ,Stirap - Abstract
We report the creation of ultracold bosonic dipolar (NaK)-Na-23-K-39 molecules in their absolute rovibrational ground state. Starting from weakly bound molecules immersed in an ultracold atomic mixture, we coherently transfer the dimers to the rovibrational ground state using an adiabatic Raman passage. We analyze the two-body decay in a pure molecular sample and in molecule-atom mixtures and find an unexpectedly low two-body decay coefficient for collisions between molecules and K-39 atoms in a selected hyperfine state. The preparation of bosonic (NaK)-Na-23-K-39 molecules opens the way for future comparisons between fermionic and bosonic ultracold ground-state molecules of the same chemical species.
- Published
- 2020
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