Spin-blockade and state lifetimes of many-hole spin states in silicon quantum dots

Abstract Hole spins in silicon quantum dots (QDs) are a promising candidate for fault-tolerant quantum computing. To achieve high-fidelity readout and high coherence required for fault tolerance, the evaluation of spin-blockade and state lifetimes is important because they can limit the qubit fidelities. In this study, we characterize these two figures of merit of manyhole qubits in silicon QDs. We report a spin-blockade lifetime of 5.1 µs, which is comparable with the values reported previously, and a spin-state lifetime of 0.91 ms, which is longer than the one measured in a few-hole silicon QD in a previous study. We furthermore provide insights into a many-hole spin state based on the estimated tunneling rate ratio.