# Charge noise induced spin dephasing in a nanowire double quantum dot with spin-orbit coupling

## TL;DR

This paper investigates how charge noise causes spin dephasing in a nanowire double quantum dot with spin-orbit coupling, revealing a nonmonotonic relationship with potential asymmetry and the influence of magnetic fields.

## Contribution

It provides an exact solution to the eigen-energies and eigenfunctions, demonstrating the complex dependence of spin dephasing on potential asymmetry and magnetic field effects.

## Key findings

- Dephasing rate peaks at a certain potential asymmetry.
- Magnetic field enhances dephasing, especially at the anti-crossing point.
- Spin dephasing exhibits nonmonotonic behavior with potential asymmetry.

## Abstract

Unexpected fluctuating charge field near a semiconductor quantum dot has severely limited the coherence time of the localized spin qubit. It is the interplay between the spin-orbit coupling and the asymmetrical confining potential in a quantum dot, that mediates the longitudinal interaction between the spin qubit and the fluctuating charge field. Here, we study the $1/f$ charge noise induced spin dephasing in a nanowire double quantum dot via exactly solving its eigen-energies and eigenfunctions. Our calculations demonstrate that the spin dephasing has a nonmonotonic dependence on the asymmetry of the double quantum dot confining potential. With the increase of the potential asymmetry, the dephasing rate first becomes stronger very sharply before reaching to a maximum, after that it becomes weaker softly. Also, we find that the applied external magnetic field contributes to the spin dephasing, the dephasing rate is strongest at the anti-crossing point $B_{0}$ in the double quantum dot.