Eur. Phys. J. B 57, 27-35 (2007)
https://doi.org/10.1140/epjb/e2007-00148-9

Transport properties of a single-quantum dot Aharonov-Bohm interferometer

¹ Department of Precision Science & Technology and Applied Physics, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
² Department of Physics, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
³ Center for the Promotion of Research in Nanoscience and Nanotechnology, Osaka University, Toyonaka, Osaka, 560-0043, Japan

Corresponding authors: ^a son@dyn.ap.eng.osaka-u.ac.jp - ^b kasai@dyn.ap.eng.osaka-u.ac.jp

Received: 12 January 2007
Revised: 12 April 2007
Published online: 25 May 2007

Abstract

We consider a two-terminal Aharonov-Bohm (AB) interferometer with a quantum dot inserted in one path of the AB ring. We investigate the transport properties of this system in and out of the Kondo regime. We utilize perturbation theory to calculate the electron self-energy of the quantum dot with respect to the intradot Coulomb interaction. We show the expression of the Kondo temperature as a function of the AB phase together with its dependence on other characteristics such as the linewidth of the ring and the finite Coulomb interaction and the energy levels of the quantum dot. The current oscillates periodically as a function of the AB phase. The amplitude of the current oscillation decreases with increasing Coulomb interaction. For a given temperature, the electron transport through the AB interferometer can be selected to be in or out of the Kondo regime by changing the magnetic flux threading perpendicular to the AB ring of the system.