Detection and measurement of the Dzyaloshinskii-Moriya interaction in double quantum dot systems

TL;DR

This paper investigates the Dzyaloshinskii-Moriya interaction in double quantum dot systems, highlighting its dependence on external field direction and proposing an experiment for detection and characterization.

Contribution

It introduces a method to detect and measure the DM interaction in quantum dots, emphasizing its directional dependence and impact on qubit behavior.

Findings

DM interaction causes anisotropic exchange coupling

Interaction strength varies with external field direction

Proposed experiment can detect and characterize the DM interaction

Abstract

Spins in quantum dots can act as the qubit for quantum computation. In this context we point out that spins on neighboring dots will experience an anisotropic form of the exchange coupling, called the Dzyaloshinskii-Moriya (DM) interaction, which mixes the spin singlet and triplet states. This will have an important effect on both qubit interactions and spin-dependent tunneling. We show that the interaction depends strongly on the direction of the external field, which gives an unambiguous signature of this effect. We further propose a new experiment using coupled quantum dots to detect and characterize the DM interaction.