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Scalable graph states are essential for measurement-based quantum computation and many entanglement-assisted applications in quantum technologies. Generation of these multipartite entangled states requires a controllable and efficient quantum device with delicate design of generation protocol. Here we propose to prepare high-fidelity and scalable graph states in one and two dimensions, which can be tailored in an atom-nanophotonic cavity via state carving technique. We propose a systematic protocol to carve out unwanted state components, which facilitates scalable graph states generations via adiabatic transport of a definite number of atoms in optical tweezers. An analysis of state fidelity is also presented, and the state preparation probability can be optimized via multiqubit state carvings and sequential single-photon probes. Our results showcase the capability of an atom-nanophotonic interface for creating graph states and pave the way toward novel problem-specific applications using scalable high-dimensional graph states with stationary qubits., Comment: 5 figures with supplemental material

In one-dimensional quantum emitter systems, the dynamics of atomic excitations are influenced by the collective coupling between emitters through photon-mediated dipole-dipole interactions. By introducing positional disorders in a portion of the atomic array, we investigate the delocalization phenomena at the interface between disordered zone and clean zone. The excitation is initialized as symmetric Dicke states in the disordered zone, and several measures are used to quantify the excitation localization. We first use population imbalance and half-chain entropy to investigate the excitation dynamics under time evolutions, and further investigate the crossover of excitation localization to delocalization via the gap ratio from the eigenspectrum in the reciprocal coupling case. In particular, we study the participation ratio of the whole chain and the photon loss ratio between both ends of the atomic chain, which can be used to quantify the delocalization crossover in the non-reciprocal coupling cases. Furthermore, by increasing the overall size or the ratio of the disordered zone under a fixed number of the whole chain, we observe that excitation localization occurs at a smaller disorder strength in the former case, while in the latter, a facilitation of the delocalization appears when a significant ratio of clean zone to disordered zone is applied. Our results can reveal the competition between the clean zone and the disordered zone sizes on localization phenomenon, give insights to non-equilibrium dynamics in the emitter-waveguide interface, and provide potential applications in quantum information processing.

We consider a three-species predator-prey system involving two competing predators and one prey. The species diffuse with nonlocal dispersal kernels with possibly non-compact support, and they interact in a heterogeneous environment moving with a positive forced speed such that the environment is favorable to the prey in the absence of predators far ahead of the shifting boundary and it is unfavorable far behind. Such systems arise in the modeling of population dynamics under the effect of a shifting environment, such as climate change. We show on the one hand the existence of waves connecting the trivial state to the unique constant positive coexistence state for any value of the forced speed. On the other hand, we show the existence of critical positive speeds for the existence of waves connecting the trivial state to the states corresponding to the absence of one or two predators.

A scheme was developed by Lepping, Berdichevsky, and Wu (Solar Phys., doi.10. 1007/ s11207-016-1040-9, 2017) [called the LBW article here] to approximate the average magnetic field magnitude (B-) profile of a "typical" magnetic cloud (MC) at/near 1AU. It was based on actual Wind MC data, taken over 21 years, that was used to modify a time shifted Bessel function (force-free) magnetic field, where shifted refers to a field that was adjusted for typical MC self-similar expansion. This was developed in the context of the Lepping, Jones, and Burlaga (J. Geophys. Res. vol. 95, p.11957, 1990) [called LJB here] MC parameter fitting model and should provide more realistic future representations of the MC's B-profile in most cases. In the LBW article, through testing, it was shown that on average it can be expected that in about 80% of the MC cases (but it varies according to the spacecrafts' actual closest approach distances) the modified model's B-profile of the MC should be significantly improved by use of this scheme. We describe how this scheme can be employed practically in modifying the LJB MC fitting model, and we test a new and slightly better (and less unwieldy) version of the scheme, the non-shifted (of Bessel functions) version, which is the one actually used in the LJB model modification. The new scheme is based on modification formulae that are slightly more accurate than the old scheme, and it is expected to improve the B-profile in approximately 83% of the cases on average. The schemes are applicable for use with data originating only at/near 1 AU, since the magnetic field and plasma data used in the development of the associated formulae were from only the Wind spacecraft, which was and is at 1 AU., Comment: accepted for publication in Solar Physics

We investigate the performance of six methods for predicting the CME time of arrival (ToA) and velocity at Earth using a sample of nine Earth-impacting CMEs between May 2010 and June 2011. The CMEs were tracked continuously from the Sun to near Earth in multi-viewpoint imaging data from STEREO SECCHI and SOHO LASCO. We use the Graduate Cylindrical Shell (GCS) model to estimate the three-dimensional direction and height of the CMEs in every image out to $\sim$200 R$_\odot$. We fit the derived three-dimensional (deprojected) height and time data with six different methods to extrapolate the CME ToA and velocity at Earth. We compare the fitting results with the in situ data from the WIND spacecraft. We find that a simple linear fit after a height of 50$R_\odot$ gives the best ToA with a total error $\pm$13 hours. For seven (78%) of the CMEs, we are able to predict the ToA to within $\pm$6 hours. These results are a full day improvement over past CME arrival time methods that only used SOHO LASCO data. We conclude that heliographic measurements, beyond the coronagraphic field of view, of the CME front made away from the Sun-Earth line are essential for accurate predictions of their time of arrival.

We use STEREO imagery to study the morphology of a shock driven by a fast coronal mass ejection (CME) launched from the Sun on 2011 March 7. The source region of the CME is located just to the east of a coronal hole. The CME ejecta is deflected away from the hole, in contrast with the shock, which readily expands into the fast outflow from the coronal hole. The result is a CME with ejecta not well centered within the shock surrounding it. The shock shape inferred from the imaging is compared with in situ data at 1 AU, where the shock is observed near Earth by the Wind spacecraft, and at STEREO-A. Shock normals computed from the in situ data are consistent with the shock morphology inferred from imaging., Comment: to appear in The Astrophysical Journal

The emission spectra of many pi-conjugated polymers and oligomers contain side-band replicas with apparent frequencies that do not match the Raman active mode frequencies. Using a time dependent model we show that in such many mode systems, the increased damping of the time dependent transition dipole moment correlation function results in an effective elimination of the vibrational modes from the emission spectrum; subsequently causing the appearance of a regularly spaced progression at a new apparent frequency. We use this damping dependent vibrational reshaping to quantitatively account for the vibronic structure in the emission spectra of pi-conjugated systems in the form of films, dilute solutions and single crystals. In particular, we show that by using the experimentally measured Raman spectrum we can account in detail for the apparent progression frequencies and their relative intensities in the emission spectrum., Comment: Presented in "Optical Probes 2005", Bangalore, India

The photoluminescence (PL) spectra of dilute solution and single crystals of distyrylbenzene show unique temperature dependent vibronic structures. The characteristic single frequency progression at high temperatures is modulated by a low frequency progression series at low temperatures. None of the series side band modes corresponds to any of the distyrylbenzene Raman frequencies. We explain these PL properties using a time dependent model with temperature dependent damping, in which the many-mode system is effectively transformed to two- and then to a single "apparent" mode as damping increases., Comment: 4 pages, 3 figures

With on- and off- resonant excitation photons, spin-resolved Auger electron spectra of epitaxial CrO$_{2}$ thin films show an experimental evidence of the spin-selective KLL Auger decay. The on-resonance O KLL Auger electrons are found to be highly spin-polarized, while the off-resonance ones with almost zero spin polarization. These results lead to conclude that the two-hole final state in KLL Auger decay is a spin-singlet. Applications to spin-resolved absorption spectroscopy are discussed., Comment: 4 pages, 3 figures

Observations in integrated light (2200-4800 A, 8 to 11 A resolution, S/N > 20) of 4 M31 globular clusters and of the cores of six gE galaxies made with the HST/FOS are presented and analyzed. These data are supplemented by IUE observations of M32, Galactic globulars and stars. From these data we measure UV colors and absorption line strength (ALS) indices, including the key NH feature at 3360 A. We find that our data divide the M31 globular clusters, Galactic globular clusters/Galactic stars, and gE galaxies into three different stellar populations. The old stellar populations of M31 globular clusters and elliptical galaxies are more similar to each other than each is to the Galactic stellar population. Of special note is that the NH feature is so strong in the spectra of M31 globulars that a large (>20) overabundance in nitrogen in these stars, relative to that in Galactic stars, is likely required. Other ALS indices (of Mg, Al) also show significant differences., Comment: 31 pages, LaTex (aaspp4), 5 tables in 7 pages; 17 jpeg figures. Alternate copy of tar.gz file available at URL: ftp://samuri.la.asu.edu/pub/burstein/ponderpap

We present a theoretical interpretation of the broad silicon and iron UV absorption features observed with the Hubble Space Telescope in the spectrum of the Schweizer-Middleditch star behind the remnant of Supernova 1006. These features are caused by supernova ejecta in SN1006. We propose that the redshifted SiII2 1260 A feature consists of both unshocked and shocked SiII. The sharp red edge of the line at 7070 km/s indicates the position of the reverse shock, while its Gaussian blue edge reveals shocked Si with a mean velocity of 5050 km/s and a dispersion of 1240 km/s, implying a reverse shock velocity of 2860 km/s. The measured velocities satisfy the energy jump condition for a strong shock, provided that all the shock energy goes into ions, with little or no collisionless heating of electrons. The line profiles of the SiIII and SiIV absorption features indicate that they arise mostly from shocked Si. The total mass of shocked and unshocked Si inferred from the SiII, SiIII and SiIV profiles is M_Si = 0.25 \pm 0.01 Msun on the assumption of spherical symmetry. Unshocked Si extends upwards from 5600 km/s. Although there appears to be some Fe mixed with the Si at lower velocities < 7070 km/s, the absence of FeII absorption with the same profile as the shocked SiII suggests little Fe mixed with Si at higher (before being shocked) velocities. The column density of shocked SiII is close to that expected for SiII undergoing steady state collisional ionization behind the reverse shock, provided that the electron to SiII ratio is low, from which we infer that most of the shocked Si is likely to be of a fairly high degree of purity, unmixed with other elements. We propose that the ambient interstellar density on the far side of SN1006 is anomalously low compared to the density around the rest of the remnant. This, Comment: 24 pages, with 8 figures included. Accepted for publication in the Astrophysical Journal