Modulation of magnetotransport in asymmetrically coupled double quantum dot system

Abstract

We study the transport properties in double quantum dots asymmetrically coupled to leads in magnetic field. We focus on the situation in which the second dot (QD2) couples with the leads with a weak hybridization function. The results shows that by tuning the energy level [Formula: see text] of QD2 one can control the conductance and its spin polarization of the system. In the absence of magnetic field [Formula: see text], with increasing [Formula: see text], the conductance shows a dip structure. This behavior of conductance results from a continuous triplet–doublet quantum phase transition. In the presence of magnetic field [Formula: see text], we obtain a perfect spin filtering with a fully-polarized conductance of up-spin or down-spin.