Spin relaxation rates in quasi-one-dimensional coupled quantum dots

TL;DR

This paper theoretically investigates spin relaxation rates in quasi-one-dimensional coupled quantum dots, highlighting how the relaxation rate peaks sharply at specific interdot-barrier widths due to level splitting, with implications for quantum control.

Contribution

It provides a detailed theoretical analysis of spin relaxation in coupled quantum dots considering all phonon modes and spin-orbit interactions, revealing a controllable sharp maximum in relaxation rate.

Findings

Spin relaxation rate peaks sharply at a specific interdot width.

The peak position depends on the external magnetic field.

All phonon modes and mechanisms are considered in the analysis.

Abstract

We study theoretically the spin relaxation rate in quasi-one-dimensional coupled double semiconductor quantum dots. We consider InSb and GaAs-based systems in the presence of the Rashba spin-orbit interaction, which causes mixing of opposite-spin states, and allows phonon-mediated transitions between energy eigenstates. Contributions from all phonon modes and coupling mechanisms in zincblende semiconductors are taken into account. The spin relaxation rate is shown to display a sharp, cusp-like maximum as function of the interdot-barrier width, at a value of the width which can be controlled by an external magnetic field. This remarkable behavior is associated with the symmetric-antisymmetric level splitting in the structure.