Spin relaxation in a two-electron quantum dot

TL;DR

This paper investigates how spin relaxation occurs in a two-electron quantum dot near a singlet-triplet transition, highlighting the roles of spin-orbit and electron-phonon interactions and explaining experimental puzzles.

Contribution

It provides a detailed analysis of spin relaxation mechanisms in two-electron quantum dots, emphasizing the dependence on ground and excited state spins and connecting theory with experimental observations.

Findings

Spin relaxation depends on the spin state of the system.

Asymmetry in relaxation explains experimental puzzles.

Relaxation rates are influenced by spin-orbit and electron-phonon interactions.

Abstract

We discuss the rate of relaxation of the total spin in the two-electron droplet in the vicinity of the magnetic field driven singlet-triplet transition. The total spin relaxation is attributed to spin-orbit and electron-phonon interactions. The relaxation process is found to depend on the spin of ground and excited states. This asymmetry is used to explain puzzles in recent high source-drain transport experiments.