Method for Full Bloch-Sphere Control of a Localized Spin via a Single Electrical Gate

TL;DR

This paper proposes a method to achieve full Bloch-sphere control of a localized electron spin in a quantum dot using only a static magnetic field and a single electric gate, by exploiting electric field dependence of the g tensor.

Contribution

It demonstrates how to manipulate the electron spin in quantum dots through electric field tuning of the g tensor, enabling full spin control with minimal hardware.

Findings

Certain quantum dot sizes allow g tensor components to change sign with electric field.

Full Bloch-sphere control can be achieved with a static magnetic field and a single vertical gate.

The method provides a pathway for scalable quantum spin control in quantum dot systems.

Abstract

We calculate the dependence on an applied electric field of the g tensor of a single electron in a self-assembled InAs/GaAs quantum dot. We identify dot sizes and shapes for which one in-plane component of the g tensor changes sign for realistic electric fields, and show this should permit full Bloch-sphere control of the electron spin in the quantum dot using only a static magnetic field and a single vertical electric gate.