Dynamics of coupled spins in quantum dots with strong spin-orbit interaction

TL;DR

This study explores how strong spin-orbit interaction affects the dynamics of two-electron spins in InAs nanowire quantum dots, revealing unique relaxation behaviors and coherent oscillations.

Contribution

It provides new insights into spin dynamics under strong spin-orbit coupling in quantum dots, highlighting differences from GaAs systems and demonstrating coherent spin evolution.

Findings

Spin relaxation depends differently on magnetic field compared to GaAs dots.

Detected oscillations indicate coherent evolution of coupled spins.

Spin-orbit interaction significantly influences spin state dynamics.

Abstract

We investigated the time dependence of two-electron spin states in a double quantum dot fabricated in an InAs nanowire. In this system, spin-orbit interaction has substantial influence on the spin states of confined electrons. Pumping single electrons through a Pauli spin-blockade configuration allowed to probe the dynamics of the two coupled spins via their influence on the pumped current. We observed spin-relaxation with a magnetic field dependence different from GaAs dots, which can be explained by spin-orbit interaction. Oscillations were detected for times shorter than the relaxation time, which we attribute to coherent evolution of the spin states.