Electron Number Dependence of Spin Triplet-Singlet Relaxation Time

TL;DR

This study measures how the spin triplet-singlet relaxation time in a GaAs quantum dot varies with electron number, revealing increased spin-orbit coupling as electrons increase from 2 to 6.

Contribution

It demonstrates the dependence of relaxation time on electron number and the role of spin-orbit coupling in multi-electron quantum dots.

Findings

T1 decreases with increasing electron number from 2 to 6.

Spin-orbit coupling strength increases with electron number.

E_ST is used as a control parameter for comparison.

Abstract

In a GaAs single quantum dot, the relaxation time T_{1} between spin triplet and singlet states has been measured for the last few even number of electrons. The singlet-triplet energy separation E_{ST} is tuned as a control parameter for the comparison of T_{1} between different electron numbers. T_{1} shows a steady decrease from 2-electrons, 4-electrons, to 6-electrons, and we found this implies an enhancement of the spin-orbital coupling strength in a multi-electron quantum dot.