Singlet-triplet relaxation induced by confined phonons in nanowire-based quantum dots

TL;DR

This paper theoretically investigates how confined phonons in nanowire quantum dots influence singlet-triplet relaxation, revealing multi-peak relaxation rates and the dominance of deformation-potential coupling.

Contribution

It provides a detailed analysis of phonon-induced relaxation mechanisms in nanowire quantum dots, highlighting the effects of confinement and coupling types.

Findings

Relaxation rates show multi-peaks as a function of magnetic field.

Relaxation is enhanced near the singlet-triplet anti-crossing.

Deformation-potential coupling generally dominates relaxation processes.

Abstract

The singlet-triplet relaxation in nanowire-based quantum dots induced by confined phonons is investigated theoretically. Due to the quasi-one-dimensional nature of the confined phonons, the singlet-triplet relaxation rates exhibit multi-peaks as function of magnetic field and the relaxation rate between the singlet and the spin up triplet state is found to be enhanced at the vicinity of the singlet-triplet anti-crossing. We compare the effect of the deformation-potential coupling and the piezoelectric coupling and find that the deformation-potential coupling dominates the relaxation rates in most cases.