Spin-resolved counting statistics as a sensitive probe of spin correlation in transport through a quantum dot spin valve

Guanjian Hu; Jing Hu; Shikuan Wang; RuiQiang Li; Yiying Yan; JunYan Luo

doi:10.1088/1361-648X/ad3da6

Spin-resolved counting statistics as a sensitive probe of spin correlation in transport through a quantum dot spin valve

J Phys Condens Matter. 2024 Apr 22;36(29). doi: 10.1088/1361-648X/ad3da6.

Authors

Guanjian Hu¹, Jing Hu¹, Shikuan Wang², RuiQiang Li¹, Yiying Yan¹, JunYan Luo¹

Affiliations

¹ Department of Physics, Zhejiang University of Science and Technology, Hangzhou 310023, People's Republic of China.
² Department of Physics, Hangzhou Dianzi University, Hangzhou 310018, People's Republic of China.

PMID: 38604158
DOI: 10.1088/1361-648X/ad3da6

Abstract

We investigate the noise in spin transport through a single quantum dot (QD) tunnel coupled to ferromagnetic (FM) electrodes with noncollinear magnetizations. Based on a spin-resolved quantum master equation, auto- and cross-correlations of spin-resolved currents are analyzed to reveal the underlying spin transport dynamics and characteristics for various polarizations. We find the currents of majority and minority spins could be strongly autocorrelated despite uncorrelated charge transfer. The interplay between tunnel coupling and the Coulomb interaction gives rise to an exchange magnetic field, leading to the precession of the accumulated spin in the QD. It strongly suppresses the bunching of spin tunneling events and results in a unique double-peak structure in the noise of the net spin current. The spin autocorrelation is found to be susceptible to magnetization alignments, which may serve as a sensitive tool to measure the magnetization directions between the FM electrodes.

Keywords: master equation; quantum dot spin valve; spin-resolved counting statistics.