Aharonov-Bohm conductance through a single-channel quantum ring: Persistent-current blockade and zero-mode dephasing
* SPEAKERS
Name
Affiliation
E-mail
Dr. Dimitry Polyakov
Institute of Nanotechnology, Karlsruhe Institute of Technology
Prof. Xin Wan(xinwan(at)apctp.org)
* HOST(Applicant)
Name
Affiliation
E-mail
-
* DATE / TIME
2010-08-02, 04:00PM
* PLACE
Conference room 503, APCTP Headquarters, POSTECH, Pohang, Korea
* ABSTRACT
I will discuss the transport properties of strongly correlated quantum rings. Particular emphasis will be put on the conceptually simplest Aharonov-Bohm interferometer: a tunnel-coupled single-channel ballistic ring, the physics of the interference and dephasing in which turns out to be remarkably rich. In particular, the conductance of the ring shows a series of interaction-induced Aharonov-Bohm resonances which, in contrast to the Coulomb-blockade oscillations, survive thermal averaging. The period of the series is given by the interaction strength. The physics behind this behavior is the blocking of the tunneling current by the circular current (Persistent-Current Blockade). The main mechanism of dephasing of the Aharonov-Bohm oscillations in the almost closed ring is due to circular-current fluctuations (Zero-Mode Dephasing). The dephasing rate is proportional to the tunneling rate and at not too low temperatures does not (!) depend on the interaction strength.
