Selective Spin Injection Controlled by Electrical way in Ferromagnet/Quantum Dot/Semiconductor system

TL;DR

This paper predicts that in a FM/QD/SC system, the polarization of injected current can be electrically controlled by gate voltage, revealing spin-dependent Kondo effects and polarization-dependent Kondo resonance suppression.

Contribution

It introduces a method to electrically control spin injection polarization in a FM/QD/SC system and explores the spin-dependent Kondo phenomena.

Findings

Polarization of current can be tuned by gate voltage above Kondo temperature.

Spin-dependent Kondo effects are observed below Kondo temperature.

Kondo resonance for up spin is suppressed as polarization increases, disappearing at P=1.

Abstract

Selective and large polarization of current injected into semiconductor (SC) is predicted in Ferromagnet (FM)/Quantum Dot (QD)/SC system by varying the gate voltage above the Kondo temperature. In addition, spin-dependent Kondo effect is also revealed below Kondo temperature. It is found that Kondo resonances for up spin state is suppressed with increasing of the polarization P of the FM lead. While the down one is enhanced. The Kondo peak for up spin is disappear at P=1.