High-Fidelity State Preparation, Quantum Control, and Readout of an Isotopically Enriched Silicon Spin Qubit

Abstract

Quantum systems must be prepared, controlled, and measured with high fidelity in order to perform complex quantum algorithms. Control fidelities have greatly improved in silicon spin qubits but state-preparation and readout fidelities have generally been poor. By operating with low electron temperatures and employing high-bandwidth cryogenic amplifiers, we demonstrate single-qubit readout visibilities $>99\mathrm{%}$, exceeding the threshold for quantum error correction. In the same device, we achieve average single-qubit control fidelities $>99.95\mathrm{%}$. Our results show that silicon spin qubits can be operated with high overall operation fidelity.