Spin Relaxation in a Quantum Dot due to Nyquist Noise

TL;DR

This paper investigates how Nyquist noise influences spin relaxation in quantum dots, highlighting the dependence on circuit resistance, magnetic field orientation, and spin-orbit interaction parameters, with implications for experimental systems.

Contribution

It introduces a detailed calculation of spin relaxation rates due to Nyquist noise, incorporating hyperfine and spin-orbit interactions, and compares these effects with other known relaxation mechanisms.

Findings

Relaxation rate is proportional to circuit resistance.

Orientation of magnetic and electric fields significantly affects relaxation.

Nyquist noise can notably impact spin relaxation in realistic quantum dot systems.

Abstract

We calculate electron and nuclear spin relaxation rates in a quantum dot due to the combined action of Nyquist noise and electron-nuclei hyperfine or spin-orbit interactions. The relaxation rate is linear in the resistance of the gate circuit and, in the case of spin-orbit interaction, it depends essentially on the orientations of both the static magnetic field and the fluctuating electric field, as well as on the ratio between Rashba and Dresselhaus interaction constants. We provide numerical estimates of the relaxation rate for typical system parameters, compare our results with other, previously discussed mechanisms, and show that the Nyquist mechanism can have an appreciable effect for experimentally relevant systems.