Kondo effect in a double quantum dot interferometer with Rashba spin–orbit interaction

Abstract

Electronic transport through a double quantum dot interferometer with Rashba spin-orbit interaction is investigated. By means of the slave-boson mean-field approximation and Green function technique, we calculated the local density of states (DOS) and the linear conductance in the Kondo regime at zero temperature. It is shown that the local DOS and the linear conductance of each spin component can be tuned by the Rashba spin-orbit interaction with help of the magnetic flux. In particular, by modulating the strength of the Rashba spin-orbit interaction properly, only one spin component electron can be allowed to transport through this structure. 1 Introduction The Kondo effect in artificial quantum dots (QD) was predicted theoretically more than two decades ago [1,2]. The phenomenon in QD occurs because of a strong antiferromagnetic coupling between the localized spin in the QD and the conduction band electrons in the electrodes through higher-order tunneling processes. The resulting correlated motion gives rise to a Kondo singularity in the density of states (DOS) at the Fermi level and the enhanced conductance. The Kondo effect in the coupled QD has attracted much attention both experimentally and theoretically [3][4][5], recently. The flexibility in tuning various parameters of coupled quantum dos has enabled the study of Kondo phenomena in great detail.In addition, the Rashba spin-orbit (RSO) interaction is an important mechanism that influences the electron-spin state in low-dimensional structures [6][7][8]. The RSO interaction comes into play by introducing an electric field that destroys the symmetry of space inversion in an arbitrary spatial direction. In QD structures, the RSO interaction give rises to an extra spin-dependent phase factor in the coupling matrix elements between the leads and the QD and the inter-level spin-flip term [10]. Hence, the RSO interaction makes the quantum transport phenomena rich and complicated [9]. Recently, Vernek et al. [10] theoretically predicted that the combination of RSO interaction and the Aharonov-Bohm (AB) effect strongly suppresses the Kondo resonance, and Lim et al. [11] found

Polaron Rashba effect in an asymmetric quantum dot

“…Electronic transport through a double quantum dot interferometer with Rashba spin-orbit interaction was studied by X.J. Liu et al [3] with means of the slave-boson mean-field approximation and Green function technique. Using the k.p method and valence force field model, X.W.…”