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| VOLUME 100 (2014) | ISSUE 12 | PAGE 946 |
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High-temperature Aharonov-Bohm effect in transport through a single-channel quantum ring
A. P. Dmitriev+*, I. V. Gornyi+*, V. Yu. Kachorovskii+*, D. G. Polyakov*, P. M. Shmakov+
+Ioffe Physico-Technical Institute of the RAS, 194021 St. Petersburg, Russia *Institut für Nanotechnologie, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
Abstract
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 discuss effects of 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 circular 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 polarization, so that the ring serves as a spin polarizer. |