A Dressed Spin Qubit in Silicon

TL;DR

This paper explores a dressed spin qubit in silicon, demonstrating enhanced coherence times and tunability, with potential for scalable quantum computing architectures.

Contribution

It introduces a dressed donor-bound electron spin in silicon as a qubit with significantly improved coherence and controllability compared to undressed spins.

Findings

Coherence times of 2.4 ms (T2*) and 9 ms (Hahn echo) for dressed spins.

Dressed states enable coupling to electric fields and mechanical oscillations.

Enhanced control and longer coherence compared to undressed qubits.

Abstract

Coherent dressing of a quantum two-level system provides access to a new quantum system with improved properties - a different and easily tuneable level splitting, faster control, and longer coherence times. In our work we investigate the properties of the dressed, donor-bound electron spin in silicon, and probe its potential for the use as quantum bit in scalable architectures. The two dressed spin-polariton levels constitute a quantum bit that can be coherently driven with an oscillating magnetic field, an oscillating electric field, by frequency modulating the driving field, or by a simple detuning pulse. We measure coherence times of $T_{2\rho}^*=2.4$ ms and $T_{2\rho}^{\rm Hahn}=9$ ms, one order of magnitude longer than those of the undressed qubit. Furthermore, the use of the dressed states enables coherent coupling of the solid-state spins to electric fields and mechanical oscillations.