Manipulation of two spin qubits in a double quantum dot using an electric field

TL;DR

This paper proposes a method for electrically manipulating spin qubits in a double quantum dot using spin-orbit interaction, enabling key quantum operations without magnetic fields, with analytical and numerical validation.

Contribution

It introduces a purely electric control scheme for spin qubits via the Dzyaloshinsky-Moriya interaction modulated by Rashba spin-orbit coupling, avoiding magnetic fields.

Findings

Successful analytical and numerical demonstrations of spin initialization and rotations.

Feasibility of electric control of spin qubits without magnetic fields.

Discussion of relaxation effects and practical implementation considerations.

Abstract

We propose purely electric manipulation of spin qubits by means of the spin-orbit interaction (SOI) {\it without magnetic field or magnets} in a double-quantum dot. All the unitary transformations can be constructed by the time-dependent Dzyaloshinsky-Moriya interaction between the two spins, which arises from the Rashba SOI modulated by electric field. As a few demonstrations, we study both analytically and numerically the three operations, i.e., (A) the spin initialization, (B) the two-spin rotation in the opposite directions, and (C) the two-spin rotation in the same direction. The effects of the relaxation and the feasibility of this proposal are also discussed.