Regular Article

The circular current in a conducting mesoscopic ring with coupled quantum dot

Department of Physics Experiment Center, Chongqing University of Technology, Chongqing 400054, P.R. China

^a e-mail: zyyxsc@sina.com

Received: 12 June 2016
Revised: 14 August 2016
Accepted: 13 September 2016
Published online: 18 November 2016

Abstract

In this paper, we investigate the circular current in the metallic ring coupled with two QDs connected with two ferromagnetic leads with the in-plane electric field ξ which is perpendicular to the wire applied to the ring by using the non-equilibrium Green’s function technique. We find that in this systems the circular current in the ring can be tuned by the voltages between left and right electrodes, the temperature, the spin polarization, and the energy of the QDs and the electric field ε. With these parameters varied, the values and direction of the circular current can be controlled, so we can control the values and the directions of the magnetic field produced at the ring center. In addition, there also has the function of spin filter in the P and has the function of suppression of the circular current for large 𝒫 of the AP. So this structure has potential applications in designing spin-based quantum devices.