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We investigate the spin-polarized electron transport through a quantum ring whose arms are embedded by one protein-like single-helical molecule and one quantum dot, respectively. It is found that the inter-arm quantum interference leads to the enhancement of the spin polarization in this structure. Moreover, when local magnetic flux is applied through the ring, the spin polarization in the electron transport process, including the polarization strength and direction, can be further adjusted. Next in the finite-bias case, the spin polarization is also apparent and can be tuned by changing the magnetic flux or the dot level. This work provides a new scheme to manipulate the spin transport based on the single-helical molecule. [ABSTRACT FROM AUTHOR]

We investigate the Andreev transports through a double-quantum-dot Cooper-pair splitter with an additional direct coupling between the dots. It is found that when finite magnetic flux is applied through this structure, its induced phase adjusts the local and crossed Andreev reflections in different manners. Moreover, in the presence of appropriate magnetic flux, the crossed Andreev reflection can be efficiently enhanced, accompanied by the suppression of the local Andreev reflection. Such a result exists in both the linear and nonlinear transport regions, even in the case of strong intradot Coulomb interaction. Therefore, such a work provides a promising scheme to enhance the splitting of the Cooper pair. [ABSTRACT FROM AUTHOR]

We investigate the transport properties of a quantum dot (QD) chain side-coupled to a pair of Majorana bound states (MBSs). It is found that the zero-bias conductance is tightly dependent on the parity of QD number. First, if a Majorana zero mode is introduced to couple to one QD of the odd-numbered QD structure, the zero-bias conductance is equal to e²/2h, but the zero-bias conductance will experience a valley-to-peak transition if the Majorana zero mode couples to the different QDs of the even-numbered QD structure. On the other hand, when the inter-MBS coupling is nonzero, the zero-bias conductance spectrum shows a peak in the odd-numbered QD structure, and in the even-numbered QD structure one conductance valley appears at the zero-bias limit. These results show the feasibility to manipulate the current in a multi-QD structure based on the QD-MBS coupling. Also, such a system can be a candidate for detecting the MBSs. [ABSTRACT FROM AUTHOR]

Ionic liquid-sensitized molecularly imprinted polymers (MIPs) based on Mn and Cu co-doped ZnIn 2 S 4 quantum dots functionalized graphene (QDs-G@ILMIPs) were prepared by a one-pot facile polymerization at room temperature. Here, the ionic liquid was used as functional monomers to provide chemical bonds for the recognition sites of target molecules. The ionic liquid was also used to improve the selectivity and adsorption capacity, and enhance the fluorescence stability and sensitivity of the MIPs for surface modification. Additionally, the Mn/Cu co-doped ZnIn 2 S 4 quantum dots could play a synergistic role in avoiding the toxicity of the heavy metals, and enhance the fluorescence performance. An increased efficiency and sensitivity of QDs-G@ILMIPs was obtained owing to the use of graphene with its large specific surface area, which effectively increased the number of binding sites to facilitate the electron transfer process. The turn-off fluorescence spectra of QDs-G@ILMIPs decreased sharply with an increasing concentration of the λ-cyhalothrin standards within the range from 1 to 350 μg g−1. The detection limit of QDs-G@ILMIPs was 0.246 μg g−1. Furthermore, the QDs-G@ILMIPs toward λ-cyhalothrin detection in real samples, as well as its recovery, reproducibility and stability, proved that the QDs-G@ILMIPs could be extensively applied for the accurate detection of pesticide residues in food samples. Image 1 • A one-pot reverse microemulsion polymerization was used to prepare QDs-G@ILMIPs at room temperature. • Ionic liquid and APTES provided chemical bonds for the recognition sites of target molecules. • Ionic liquid enhanced the fluorescence stability and sensitivity of the MIPs with surface modification. • Mn/Cu co-doped ZnIn 2 S 4 QDs avoided the toxicity, and enhanced the fluorescence performance. • Graphene increased the number of binding sites to facilitate the electron transfer process. [ABSTRACT FROM AUTHOR]

Motivated by the result in the recent work [A. Slachter, F. L. Bakker, J.-P. Adam, and B. J. van Wees, Nature Phys. 6, 879 (2010)], we research the thermally driven electron transport through a quantum dot (QD) coupled to two ferromagnetic leads and one normal-metallic lead. By applying temperature bias between the two ferromagnetic leads, we calculate the charge and spin currents in the normal-metallic lead and the spin accumulation in the QD. As a result, we observe that the charge and pure spin currents in the normal-metallic lead, as well as the spin accumulation in the QD, can be independently driven by the temperature bias. According to these results, we propose this system to be a promising candidate of the nanoswitch for the charge and spin current manipulation. [ABSTRACT FROM AUTHOR]

The Fano effect in electron transport through a parallel-coupled multi-quantum-dot system is theoretically studied by adjusting the asymmetries of dot-lead couplings. As a result, we find that three kinds of Fano lineshapes emerge in the linear conductance spectra. Namely, when the dot-lead couplings are up-down asymmetric, two kinds of Fano effects occur with the tuning of local magnetic fluxes. The other Fano effect is observed in the case of left-right asymmetry of the dot-lead couplings, which is tightly dependent on the dot number. We then transform the Hamiltonian into molecular orbital representation and discuss the three kinds of Fano interference mechanisms in detail. It is observed that the coupling manners between the leads and molecular states are the key factors to induce the Fano antiresonance. Since the abundant Fano effects, we consider such a structure to be a candidate of a thermoelectric device. We believe that the numerical results help to understand the Fano effect of the parallel-coupled multi-quantum-dot structure. [ABSTRACT FROM AUTHOR]

We present a detailed analysis about the changes of the orbital electron-correlation effects in one quantum-dot circuit, by considering finite couplings between the quantum dots and Majorana zero modes (MZMs). It is found that the dot-MZM couplings complicate the orbital-Kondo effect, because the orbital correlation occurs between the localized states in the quantum dots and the continuum hybridized states induced by the indirect metal-MZM couplings. When two of such correlation exist in pair, they have an opportunity to induce a long-range RKKY correlation, which is related to the MZMs. Further investigation shows that this RKKY interaction leads to the anomalous fractional Josephson effect. Our work can be helpful in clarifying the influence of MZM on the orbital electron correlation effects. [ABSTRACT FROM AUTHOR]

By applying a symmetric dipolar spin battery in a parallel-coupled quantum-dot (QD) structure, the spin accumulation in the QDs is investigated. We find that the spin accumulation can be achieved via electrically adjusting the left-right antisymmetry of the QD-lead couplings or introducing different magnetic fluxes through the sub-rings of this system. And, the spin accumulation properties are closely dependent on the number of QDs in this structure. Compared with the electrical method, the magnetic method is more efficient to manipulate the spin accumulation. When the intradot Coulomb interaction is considered, the electrically induced spin accumulation is somewhat suppressed, but in the magnetic method the spin accumulation is efficiently enhanced. We believe that the results can be observed in the experiment of spintronics, which provides an alternative scheme for spin manipulation. [ABSTRACT FROM AUTHOR]

In this paper, we study the electron properties of an Aharonov-Bohm interferometer with an embedded quantum dot (QD) by considering the leads of spin bias. As a result, it is found that a local magnetic flux through the structure can efficiently induce spin accumulation in the QD, unaccompanied by any charge transfer, and it shows that the direction and magnitude of the spin accumulation are tightly dependent on the interplay between the magnetic flux and spin bias. Based on the calculated results, we propose such a structure to be a candidate of the spin-manipulating device. [ABSTRACT FROM AUTHOR]

By introducing local Rashba spin-orbit interaction in a three-terminal quantum dot ring, we calculate the currents induced by thermoelectric effect. It shows that, when a temperature bias is applied between the source and drains, there emerge apparent spin currents in the two drains. We find, via adjusting the structure parameters, that an electron from the source will choose its drain according to its spin index. Due to the advances in nanodevice fabrication, this structure can be constructed, and then we believe that it can be a candidate of the spin-manipulating device. [ABSTRACT FROM AUTHOR]

The impurity-modulated electron transport properties in a double quantum dot (QD) Aharonov-Bohm ring are theoretically studied, by considering impurities locally and nonlocally coupled to the QDs in the ring arms, respectively. It is found that the impurities influence the electron transport in a nontrivial way: in the case of zero magnetic flux, a single-level impurity leads to the appearance of Fano line shapes in the conductance spectra, and the positions of Fano antiresonances are determined by both the impurity-QD couplings and the QD levels separated from the Fermi level; whereas when a magnetic flux is introduced with the phase factor [lowercase_phi_synonym]=π the Breit-Wigner line shapes appear in the conductance curves. Compared with the local-impurity case, nonlocal impurities alter the conductance period versus the magnetic flux. In addition, when many-body effect is considered within the second-order approximation, we find the important role of the Coulomb interaction in modifying the electron transport. [ABSTRACT FROM AUTHOR]

Quantum dot superlattices offer prospects for new generations of semiconductor devices. One possible recently suggested application is in tandem solar cells based entirely on silicon, using confinement in the quantum dot to control the cell band gap. In this paper, we use the effective mass approach to calculate the conduction band structure of a three-dimensional silicon quantum dot superlattice with the dots embedded in a matrix of silicon dioxide, silicon nitride, or silicon carbide. The quantum dot superlattice is modeled as a regularly spaced array of equally sized cubic dots in the respective matrix. Incorporating the effect of silicon anisotropic effective mass is shown to reduce both the degeneracies of the isotropic solutions and the energy separation between states. Electron densities of state and mobilities are derived from the band structure data. Theoretical results for the effect of dot size, interdot distance, and matrix material have been obtained. These results clarify the required design features of silicon quantum dot superlattices for the proposed all-silicon tandem solar cells. [ABSTRACT FROM AUTHOR]

Abstract We study the transport properties of a quantum dot (QD) fabricated by a quantum anomalous Hall insulator. It is found that energy levels of the QD are quantized due to the quantum confinement effect, which leads to the appearance of the resonant-tunnelling phenomenon at low temperature. We also find that topological edge states form around the boundary of the QD, coexisting with the bulk states inside the QD. The electron transmission through the channels of the edge and bulk states drives the Fano interference, manifested as the asymmetric lineshape of the linear conductance spectrum. In addition, the spin polarization of this system is present. It shows that the spin-polarized current can be realized even in the absence of the external magnetic field, because of the breaking the time-reversal symmetry. Highlights • We study the transport through a quantum dot fabricated by a quantum anomalous Hall insulator. • Topological edge states form around the boundary of the QD, coexisting with the bulk states inside the QD. • Transmission through the channels of the edge and bulk states drives the Fano interference. • Spin-polarized current is realized even in the absence of the external magnetic field. • The spin filtering is found to be mainly induced by the bulk states rather than the edge states. [ABSTRACT FROM AUTHOR]

We investigate the thermoelectric and thermospin effects in a quantum ring whose arms are embedded by one protein-like single-helical molecule and one quantum dot, respectively. It shows that both the thermoelectric and thermospin effects are very distinct in this system. If one local magnetic flux is introduced through this ring, the thermospin effect can be efficiently enhanced, accompanied by the weakness of thermoelectric effect. Therefore, this work can be helpful for the achievement of the thermoelectric and thermospin effects, respectively. [ABSTRACT FROM AUTHOR]

We investigate the electron transport through a quantum dot connected with two ferromagnetic leads, by coupling one Majorana doublet laterally to the quantum dot. It is found that Majorana doublet keeps the value of zero-bias conductance to be independent of the shift of structural parameters, including dot level, relative lead-magnetization direction, and magnetic field on the dot. Even in the cases of asymmetric dot-lead couplings, the zero-bias conductance is weakly dependent on the relative lead-magnetization direction. On the other hand, when Majorana doublet is replaced by Majorana singlet, the zero-bias conductance value becomes sensitive to the structural parameters. Via analyzing the respective particle motion processes, the different influences of Majorana doublet and singlet are explained. We believe that this work can be helpful for understanding the peculiar properties of Majorana doublet. [ABSTRACT FROM AUTHOR]

We present a comprehensive analysis about the transport properties of a quantum dot (QD) system with a side-coupled Majorana zero mode. Our calculation result shows that when the coupling manners between the two leads and QDs are identical, the local Andreev reflection and the interlead normal tunneling have the same magnitude at the zero-bias limit. Accordingly, the zero-bias conductance value is always equal to e 2 /2 h , which is exactly one half of the resonant-tunneling conductance. This result is independent of the level number and the level distribution in the single-QD case, and in the coupled-QD case it is irrelevant to the geometry of the QD molecule. The universal transport property is a powerful evidence for the feasibility to detect the MBSs based on a QD circuit. This result also means that the QD condition is not a key factor to achieve the detection. On the other hand, if the decoupling phenomenon appears, the Majorana zero mode may play a trivial role in contributing to the conductance property. [ABSTRACT FROM AUTHOR]

We investigate the electron transport through a graphene quantum dot with one line defect, by coupling the dot to two normal metallic leads. It is found that in the cases of the leads coupling to the same-type edges of the dot, the presence of line defect enhances the conductance at the Dirac point by inducing a new conductance peak or strengthening the original conductance peak. Such results are irrelevant to the graphene dot size. On the other hand, if the leads couple to the different-type edges of the dot, the line defect will induce two new conductance peaks near the Dirac point. The conductance enhancement is considered to originate from the fact that one bound state at the Dirac point induced by the line defect couples to the leads, which provides an additional channel for electron motion. Nevertheless, different dot-lead coupling manners change the contribution of the new channel to the electron motion, leading to the complicated transport results. These results show that the line-defect-existed graphene quantum dot will be beneficial to the realization of electron transport manipulation. [ABSTRACT FROM AUTHOR]

Abstract: We discuss the influence of local impurities on the thermoelectric effect in a parallel double quantum dot (QD) structure. It is first found that in this structure, the Fano effect contributes significantly to the enhancement of thermoelectric efficiency, especially in the case of ϕ = π. Next, impurities are introduced to couple to the QDs, respectively. We readily find that regardless of which QD is coupled to a local impurity, the thermoelectric efficiency can be enhanced by the strengthening of impurity–QD coupling. This means that the destruction of the Fano interference is not the necessary condition to suppress the thermoelectric effect. Accordingly, we hope that the numerical results can help to understand the role of impurities in adjusting the thermoelectric properties of the QD structure. [Copyright &y& Elsevier]

The electron transport in a semiconducting armchair graphene nanoribbon with line defect is theoretically investigated, by coupling it to two normal metallic leads. It is found that the line defect induces a new localized quantum state near the Dirac point, and that the coupling between this state and the leads provides a channel for the resonant tunneling. This means that such a finite-size nanoribbon can be viewed as a quantum dot. When two line defects are present simultaneously, a coupled quantum dot forms, leading to the splitting of the conductance peaks. With these results, we propose such a structure to be a promising candidate of an electron transistor. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Abstract: The thermal transport properties of a quantum dot structure with spin bias in the leads are investigated. We find that the spin bias can induce the thermal rectification phenomenon, and it becomes more apparent in the presence of Coulomb interaction. Accordingly, such a structure can be viewed as a candidate of thermal rectifier. In view of the thermal rectification results, we also consider that the spin bias in a quantum dot structure can be detected with the thermal method. [Copyright &y& Elsevier]

By means of the exact diagonalization approach, the Josephson and persistent currents in a superconductor/quantum-dot ring/superconductor (S/QDR/S) structure are theoretically investigated. The ground state is obtained within zero bandwidth approximation in which the superconductors are replaced by effective local pairing potentials. It is found that Josephson current can flow through this structure in the presence of various electron correlations. Furthermore, in the half-filled case, a novel 0-π transition behavior is observed, which arises from the interplay of interdot antiferromagnetic coupling and electron correlations. When the symmetry of the two arms in the QDR is broken down, the quantum interference efficiently causes the persistent current magnification, even in the case of equilibrium and zero magnetic flux. [ABSTRACT FROM AUTHOR]

Thermoelectric properties of a quantum dot (QD) connected to two metal leads are studied, where the QD is fabricated by the quantum anomalous Hall insulator. Surface states emerge at the edge of the QD due to the bulk‐boundary correspondence, while bulk states spread over the whole QD. Fano interference will occur between tunneling via surface and bulk states, which leads to asymmetric lineshape and minimum in the transmission and electric conductance spectrums. Both Seebeck coefficient and thermoelectric figure of merit are enhanced greatly in the energy regime of Fano interference. In addition, it is shown that Fano interference and thermoelectric properties can be well tuned by magnetic field. [ABSTRACT FROM AUTHOR]

The spin accumulation properties of a multi-arm Aharonov-Bohm-Fano interferometer are investigated by considering spin bias in the leads. We find that the spin accumulations in the quantum dots (QDs) can be adjusted independently by changing the magnetic fluxes through the sub-rings formed by the QD-lead and lead-lead couplings. When analyzing the quantum interference effect, we find that the Aharonov-Bohm-Fano interference mechanism is a necessary condition to realize the spin accumulation. Based on the numerical results, we propose that such a structure has a significant potential as a candidate for a spin-manipulating device. [ABSTRACT FROM AUTHOR]

We investigate the Andreev reflections in a single-dot quantum ring with one s-wave superconductor side-coupled to the quantum dot, by considering the presence of local Rashba interaction and magnetic flux. It shows that in this system, the local Rashba interaction induces apparent spin polarizations of the local Andreev reflections, with their directions depending on the Rashba interaction and the lead index, respectively. Nevertheless, the crossed Andreev reflection cannot be polarized, and its magnitude can be adjusted by the threaded local magnetic flux. We propose this structure to be the promising candidate for achieving the manipulation of Andreev reflections. [ABSTRACT FROM AUTHOR]

By coupling one quantum dot to a normal metal, the Kondo structure is constructed, and then its change is investigated in the case of the dot connected with a DIII-class topological superconductor supporting Majorana doublets at its ends. It is observed that Kondo correlations occur between the localized state in the dot and two continuum states simultaneously, i.e., the continuum state in the metal and the continuum Andreev reflection state between the metal and topological superconductor. This causes the Kondo-model Hamiltonian to be topologically protected by the SU(2)s⋊ZT2 symmetry. Besides, the system Kondo temperature can be altered via adjusting the structural parameters. This work clarifies the special influence of Majorana doublet on the Kondo effect. [ABSTRACT FROM AUTHOR]

In this work, Fe 3 O 4 and metal–organic framework MIL-101(Fe) composites (Fe 3 O 4 /MIL-101(Fe)) was demonstrated to possess excellent catalytic property to directly catalyze luminol chemiluminescence without extra oxidants. We utilized Fe 3 O 4 /MIL-101(Fe) to develop a ultra-sensitive quantitative analytical method for H 2 O 2 and glucose. The possible mechanism of the chemiluminescence reaction had been investigated. Under optimal conditions, the relative chemiluminescence intensity was linearly proportional to the logarithm of H 2 O 2 concentration in the range of 5–150 nM with a limit of detection of 3.7 nM (signal-to-noise ratio = 3), and glucose could be linearly detected in the range from 5 to 100 nM and the detection limit was 4.9 nM (signal-to-noise ratio = 3). Furthermore, the present approach was successfully applied to quantitative determination of H 2 O 2 in medical disinfectant and glucose in human serum samples. [ABSTRACT FROM AUTHOR]

We pay attention to the supercurrent in one Josephson junction embedded by coupled double quantum dots, by taking the interdot Coulomb interaction into account. It is found that this interaction can change the Josephson phase transition initiated by the intradot Coulomb repulsion, and its effect is strongly dependent on the structural symmetry of the Josephson junction. In comparison with the parallel-coupled and T-shaped double-dot cases, the influence of interdot Coulomb interaction is relatively weak in the serially-coupled double-dot geometry. All the supercurrent properties are discussed by analyzing the interplay between the Cooper-pair correlation and the Kondo effect in different geometries. We believe that this work can be helpful in understanding the co-influence of intradot and interdot Coulomb interactions on the Josephson phase transition. [ABSTRACT FROM AUTHOR]

We investigate the electron transport through the T-shaped quantum-dot (QD) structure theoretically, by coupling a Majorana zero mode to the terminal QD. It is found that in the double-QD configuration, the presence of the Majorana zero mode can efficiently dissolve the antiresonance point in the conductance spectrum while inducing a conductance peak to appear at the same energy position. In the case of asymmetric QD-lead coupling, such a valley-to-peak transition induced by the Majorana zero mode still exists. Next, we observe in the multi-QD case that at the zero-bias limit, the conductance values are always the same as the double-QD result, independent of the parity of the QD number. We believe that all these results can be helpful for understanding the properties of Majorana bound states. [ABSTRACT FROM AUTHOR]

Abstract: By means of the exact diagonalization approach, the Josephson current in a T-shaped double quantum dot structure is theoretically investigated. The ground state is obtained within zero bandwidth approximation in which the superconductors are replaced by effective local pairing potentials. It is found that Josephson current can flow through this structure in the presence of various electron correlations. Furthermore, in the half-filled case, a novel transition behavior is observed, which arises from the interplay of interdot antiferromagnetic coupling and electron correlations. [Copyright &y& Elsevier]

Abstract We investigate the Aharonov-Bohm (AB) effect in the parallel double-quantum-dot structure, by introducing an additional s -wave superconductor to couple to the quantum dots. It is found that the AB oscillation of the electron tunneling is different from the superconductor-absent result. Meawhile, the local and crossed Andreev reflections exhibit their special oscillation behaviors, with the change of the local magnetic flux. This means that the AB effect plays an important role in manipulating the complicated quantum transport through this system. We believe that this work can be helpful for understanding the AB oscillation in the presence of Andreev reflection processes. • We investigate AB effect in the parallel double--dot structure by introducing a superconductor. • The AB oscillation of electron tunneling is different from the superconductor-absent result. • The local and crosses Andreev reflections exhibit special oscillation behaviors. • The AB effect plays an important role in manipulating the quantum transport through this system. • This work can be helpful for understanding the AB oscillation in the presence of Andreev reflection. [ABSTRACT FROM AUTHOR]

Abstract We evaluate the quantum transport through one mesoscopic circuit with its embedded quantum dot coupled to the Majorana bound states (MBSs) at the ends of one topological-superconductor nanowire. The calculation results show that when the MBSs co-couple to the dot, antiresonance effect has an opportunity to take place, and the antiresonance point is related to the inter-MBS coupling. Moreover, once the dot-MBS coupling strengths are equal to each other, the Fano effect takes place, manifested as the Fano lineshape in the transmission-function spectrum. The results in this work can provide new information for the understanding of the MBS-contributed quantum transport through quantum-dot systems. Highlights • We evaluate quantum transport through one mesoscopic circuit with its quantum dot coupled to MBSs. • The results show that when two MBSs co-couple to the dot, antiresonance effect takes place. • The antiresonance point is related to the inter-MBS coupling. • Once the dot-MBS coupling strengths are equal, the Fano effect can be observed. • These provide new information for understanding the MBS-contributed quantum transport. [ABSTRACT FROM AUTHOR]

We present a detailed analysis about the changes of the orbital electron-correlation effects in one quantum-dot circuit, by considering finite couplings between the quantum dots and Majorana zero modes (MZMs). It is found that the dot-MZM couplings complicate the orbital-Kondo effect, because the orbital correlation occurs between the localized states in the quantum dots and the continuum hybridized states induced by the indirect metal-MZM couplings. When two of such correlation exist in pair, they have an opportunity to induce a long-range RKKY correlation, which is related to the MZMs. Further investigation shows that this RKKY interaction leads to the anomalous fractional Josephson effect. Our work can be helpful in clarifying the influence of MZM on the orbital electron correlation effects.

We construct one mesoscopic circuit in which one quantum dot couples to one DIII-class topological superconductor and one s -wave superconductor, in addition to its connection with the metallic lead. And then, the Andreev reflection current in the metallic lead is evaluated. It is found that the two kinds of superconductors drive the Andreev reflection in the constructive manner. Next as finite superconducting phase difference is taken into account, the Andreev reflection oscillates in period π 2 , and it can be suppressed in the low-energy region if the superconducting phase difference is ( n + 1 2 ) π 2 ( n ∈ Integer ). Such a result is almost independent of the increase of the intradot Coulomb interaction. Therefore, this structure can assist to realize the manipulation of the Andreev reflection. Also, the result in this work provides useful information for understanding the property of the DIII-class topological superconductor. [ABSTRACT FROM AUTHOR]

This work focuses on one Josephson junction with a side-coupled magnetic impurity. And then, the Josephson phase transition is theoretically investigated, with the help of the exact diagonalization approach. It is found that even in the absence of intradot Coulomb interaction, the magnetic impurity can efficiently induce the phenomenon of Josephson phase transition, which is tightly related to the spin correlation manners (i.e., ferromagnetic or antiferromagnetic) between the impurity and the junction. Moreover, the impurity plays different roles when it couples to the dot and superconductor, respectively. This work can be helpful in describing the influence of one magnetic impurity on the supercurrent through the Josephson junction. [ABSTRACT FROM AUTHOR]

We theoretically investigate the electronic transport through a parallel-coupled multi-quantum-dot system, in which the terminal dots of a one-dimensional quantum-dot chain are embodied in the two arms of an Aharonov–Bohm interferometer. It is found that in the structures of odd(even) dots, all their even(odd) molecular states have opportunities to decouple from the leads, and in this process antiresonance occurs which are accordant with the odd(even)-numbered eigenenergies of the sub-molecule without terminal dots. Next when Majorana zero modes are introduced to couple laterally to the terminal dots, the antiresonance and decoupling phenomena still co-exist in the quantum transport process. Such a result can be helpful in understanding the special influence of Majorana zero mode on the electronic transport through quantum-dot systems. [ABSTRACT FROM AUTHOR]

In this work, we investigate the effect of PT -symmetric complex potentials on the transport properties of one non-Hermitian system, which is formed by a parallel coupled double-quantum-dot geometry. It is found that the PT -symmetric complex potentials take pronounced effects to the transport properties of such a system, manifested as the occurrence of antiresonance. In the presence of the interdot Coulomb interaction, such potentials lead to the shift and increase of the antiresonance points, dependent on the Coulomb interaction strength. This study exhibits the special impact of the interplay between the interdot Coulomb interaction and PT -symmetric potentials on the quantum transport behaviors. [ABSTRACT FROM AUTHOR]