Single-shot readout of hole spins in Ge

TL;DR

This paper demonstrates single-shot readout of hole spins in germanium quantum dots using radio-frequency reflectometry, revealing long spin relaxation times and high potential for qubit applications.

Contribution

The study introduces a high-bandwidth RF reflectometry method enabling single-shot readout of hole spins in Ge, with detailed analysis of fidelity limits and spin lifetimes.

Findings

Spin relaxation time of about 90 μs at 500 mT

High charge readout fidelities achieved

Potential for high-visibility hole spin qubits

Abstract

The strong atomistic spin orbit coupling of holes makes single-shot spin readout measurements difficult because it reduces the spin lifetimes. By integrating the charge sensor into a high bandwidth radio-frequency reflectometry setup we were able to demonstrate single-shot readout of a germanium quantum dot hole spin and measure the spin lifetime. Hole spin relaxation times of about 90 $\mu$s at 500\,mT are reported. By analysing separately the spin-to-charge conversion and charge readout fidelities insight into the processes limiting the visibilities of hole spins has been obtained. The analyses suggest that very high hole visibilities are feasible at realistic experimental conditions underlying the potential of hole spins for the realization of viable qubit devices.