Realization of arbitrary single-qubit gates through control of spin-orbit couplings in semiconductor nanowires

TL;DR

This paper presents a theoretical method to implement arbitrary single-qubit gates using spin-orbit couplings in semiconductor nanowires, enabling lossless and precise quantum control.

Contribution

It introduces a novel scheme combining Dresselhaus and Rashba SOC units to realize a universal set of lossless single-qubit gates in semiconductor nanowires.

Findings

Universal single-qubit gates achieved with series connection of SOC units

All gates are lossless due to total transmission

A ballistic spintronic switch is proposed

Abstract

We propose a theoretical scheme to realize arbitrary single-qubit gates through two simple device units: one-dimensional semiconductor wires with Dresselhaus spin-orbit coupling (SOC) and Rashba SOC, separately. Qubit information coded by the electron spin can be accurately manipulated by the SOC when crossing the semiconductor wire. The different manipulative behaviors in Dresselhaus and Rashba wires enable us to make the diverse quantum logic gates. Furthermore, by connecting the Dresselhaus and Rashba units in series, we obtain a universal set of single qubit gates: Hadamard, phase, and $\pi /8$ gates, inferring that an arbitrary single qubit gate can be achieved. Because the total transmission is satisfied in the two device units, all the logic gates we have obtained are lossless. In addition, a ballistic spintronic switch is proposed in the present investigation.