Fast electron spin flips via strong subcycle electric excitation

Abstract

An important goal in quantum information processing is to reduce the duration of quantum-logical operations. Motivated by this, we provide a theoretical analysis of electrically induced fast dynamics of a single-electron spin-orbit qubit. We study the example of a one-dimensional quantum dot with Rashba spin-orbit interaction and harmonic driving, and focus on the case of strong driving, when the real-space oscillation amplitude of the driven electron is comparable to the width of its wave function. We provide simple approximate analytical relations between the qubit Larmor frequency, the shortest achievable qubit-flip time, and the driving amplitude required for the shortest achievable qubit flip. We find that these relations compare well with results obtained from numerical simulations of the qubit dynamics. Based on our results, we discuss practical guidelines to maximize speed and quality of electric single-qubit operations on spin-orbit qubits.