For solid-state spin qubits, single-gate RF readout can help minimise the number of gates required for scale-up to many qubits since the readout sensor can integrate into the existing gates required to manipulate the qubits (Veldhorst 2017, Pakkiam 2018). However, a key requirement for a scalable quantum computer is that we must be capable of resolving the qubit state within single-shot, that is, a single measurement (DiVincenzo 2000). Here we demonstrate single-gate, single-shot readout of a singlet-triplet spin state in silicon, with an average readout fidelity of 82.9% at a 3.3kHz measurement bandwidth. We use this technique to measure a triplet T− to singlet S0 relaxation time of 0.62ms in precision donor quantum dots in silicon. We also show that the use of RF readout does not impact the maximum readout time at zero detuning limited by the S0 to T− decay, which remained at approximately 2ms. This establishes single-gate sensing as a viable readout method for spin qubits.
@article{arxiv.1809.01802,
title = {Single-shot single-gate RF spin readout in silicon},
author = {P. Pakkiam and A. V. Timofeev and M. G. House and M. R. Hogg and T. Kobayashi and M. Koch and S. Rogge and M. Y. Simmons},
journal= {arXiv preprint arXiv:1809.01802},
year = {2018}
}