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

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 $π/8$ 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.