Anisotropy and suppression of spin--orbit interaction in a GaAs double quantum dot

TL;DR

This paper investigates how to control spin-flip tunneling in GaAs double quantum dots, enabling measurement of spin--orbit coefficients and high on/off switching of spin--orbit effects, with implications for quantum information processing.

Contribution

It introduces methods to tune spin--orbit interaction in GaAs quantum dots by adjusting tunneling direction and magnetic field orientation, facilitating precise control of spin dynamics.

Findings

Spin-flip tunneling rates measured in the Pauli spin blockade regime.

Tuning of spin--orbit interaction achieved with high on/off ratio.

Spin lifetimes of up to 10 seconds demonstrated.

Abstract

The spin-flip tunneling rates are measured in GaAs-based double quantum dots by time-resolved charge detection. Such processes occur in the Pauli spin blockade regime with two electrons occupying the double quantum dot. Ways are presented for tuning the spin-flip tunneling rate, which on the one hand gives access to measuring the Rashba and Dresselhaus spin--orbit coefficents. On the other hand they make it possible to turn on and off the effect of SOI with a high on/off-ratio. The tuning is accomplished by choosing the alignment of the tunneling direction with respect to the crystallographic axes, as well as by choosing the orientation of the external magnetic field with respect to the spin--orbit magnetic field. Spin-lifetimes of 10 s are achieved at a tunnel rate close to 1 kHz.