Probing the magnitude and orientation of the effective nuclear magnetic field in a single quantum dot using finite-frequency shot noise

Abstract

In the III–V quantum dot (QD) systems, e.g., GaAs, InP, and InAs, the nuclear spins of their lattice atoms are nonzero, and the hyperfine interaction between these nuclear spins and the localized electron spins is the dominant mechanism of electron spin relaxation at low temperatures. Consequently, the quantitative extraction of information on the magnitude and orientation of the effective nuclear magnetic field in QD systems is important for a deeper understanding of their spin dynamics. In this work, the Fano factor of the finite-frequency shot noise of electron transport through a QD system with an effective nuclear magnetic field weakly coupled to the two ferromagnetic leads is investigated. It is numerically demonstrated that the position and the height of the peak of the Fano factor of the finite-frequency shot noise can be used to quantitatively extract the magnitude and orientation (polar angle) of the effective nuclear magnetic field, respectively. The predicted results therefore suggest an alternative way to quantitatively determine the magnitude and orientation of the effective nuclear magnetic field in a single QD system.