Aharonov-Bohm conductance of a disordered single-channel quantum ring

Shmakov, P. M.; Дмитриев, А. П.; Kachorovskii, V. Yu.

doi:10.1103/physrevb.87.235417

Cited by 21 publications

(28 citation statements)

References 57 publications

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“…Eqs. (49), (70), (71), and (76) of the main text]. By Consider first the classical term in the conductance, which involves the product of two Green functions with the same chirality and is given by the sum over (n, m) and (n ′ , m ′ ).…”

Section: Figmentioning

confidence: 99%

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Spin-charge separation in an Aharonov-Bohm interferometer

et al. 2017

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We study manifestations of spin-charge separation (SCS) in transport through a tunnel-coupled interacting single-channel quantum ring. We focus on the high-temperature case (temperature T larger than the level spacing ∆) and discuss both the classical (flux-independent) and interference contributions to the tunneling conductance of the ring in the presence of magnetic flux. We demonstrate that the SCS effects, which arise solely from the electron-electron interaction, lead to the appearance of a peculiar fine structure of the electron spectrum in the ring. Specifically, each level splits into a series of sublevels, with their spacing governed by the interaction strength. In the high-T limit, the envelope of the series contains of the order of T /∆ sublevels. At the same time, SCS suppresses the tunneling width of the sublevels by a factor of ∆/T . As a consequence, the classical transmission through the ring remains unchanged compared to the noninteracting case: the suppression of tunneling is compensated by the increase of the number of tunneling channels. On the other hand, the fluxdependent contribution to the conductance depends on the interaction-induced dephasing rate which is known to be parametrically increased by SCS in an infinite system. We show, however, that SCS is not effective for dephasing in the limit of weak tunneling. Moreover, generically, in the almost closed ring, the dephasing rate does not depend on the interaction strength and is determined by the tunneling coupling to the leads. In certain special symmetric cases, dephasing is further suppressed. Similar to the spinless case, the high-T conductance shows, as a function of magnetic flux, a sequence of interaction-induced sharp negative peaks on top of the classical contribution.

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Section: Figmentioning

confidence: 99%

“…4) instead of the delta functions of zero width as in Eqs. (49) and (70). In order to find the smooth envelope,K(t), of the function K(t), we integrate Eq.…”

Section: Appendix A: Dyson Equationmentioning

confidence: 99%

Spin-charge separation in an Aharonov-Bohm interferometer

et al. 2017

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“…The effect of disorder on the high temperature transport through a quantum ring depends on the range of impurity potential [40]. In the absence of electron-electron interaction, the short range poten tial broadens the AB antiresonances, while the long range smooth disorder induces negative resonant peaks at integer values of the flux.…”

Section: Introductionmentioning

confidence: 99%

“…The amplitude of trans mission through the ring t(φ, ⑀) is given by the sum of the amplitudes of the trajectories that connect contact a to contact b (Fig. 1), including those with multiple backscattering by the contacts [38,40]:…”

Section: Introductionmentioning

confidence: 99%

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High-temperature Aharonov-Bohm effect in transport through a single-channel quantum ring

et al. 2015

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We overview transport properties of an Aharonov-Bohm interferometer made of a single channel quantum ring. Remarkably, in this setup, essentially quantum effects survive thermal averaging: the high temperature tunneling conductance G of a ring shows sharp dips (antiresonances) as a function of magnetic flux. We dis cuss effects of the electron-electron interaction, disorder, and spin-orbit coupling on the Aharonov-Bohm transport through the ring. The interaction splits the dip into series of dips broadened by dephasing. The physics behind this behavior is the persistent current blockade: the current through the ring is blocked by the circular current inside the ring. Dephasing is then dominated by tunneling induced fluctuations of the circu lar current. The short range disorder broadens antiresonances, while the long range one induces additional dips. In the presence of a spin-orbit coupling, G exhibits two types of sharp antiresonances: Aharonov-Bohm and Aharonov-Casher ones. In the vicinity of the antiresonances, the tunneling electrons acquire spin polar ization, so that the ring serves as a spin polarizer. Fig. 1. Single channel quantum ring and its energy levels.

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Aharonov–Bohm‐Like Flux Effects on the Landauer Conductance in Graphene Wormholes

et al. 2022

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In this work, the graphene wormhole in two cases, i) free case and ii) in the presence of an Aharonov–Bohm (AB)‐like magnetic field are studied. To achieve the objective, the massless Dirac equation is solved in the background of a catenoid metric. As this system does not support exact solutions due to the considered background, the scattering‐state solutions are obtained by means of the Born approximation. In both cases, the Landauer formalism is used to obtain approximate expressions for the conductance. For the free case, a minimum conductance, which is independent of system parameters is found. For the case with an AB‐like magnetic field, the results show that the conductance can be modulated by means of the parameter related to magnetic flux. In addition, a special case where a null magnetic flux generates an oscillatory conductance is analyzed.

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Aharonov-Bohm conductance of a disordered single-channel quantum ring

Cited by 21 publications

References 57 publications

Spin-charge separation in an Aharonov-Bohm interferometer

Spin-charge separation in an Aharonov-Bohm interferometer

High-temperature Aharonov-Bohm effect in transport through a single-channel quantum ring

Aharonov–Bohm‐Like Flux Effects on the Landauer Conductance in Graphene Wormholes

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