Time-resolved single-shot single-gate RF spin readout in silicon*

For solid-state spin qubits, single-gate RF readout can minimise the number of gates required for scale-up since the readout sensor can integrate into the existing gates used to manipulate the qubits [1][2]. However, state of the art topological error correction codes benefit from the ability to resolve the qubit state within single-shot, that is, without repeated measurements [3]. Here we show single-gate, single-shot readout of a singlet-triplet spin state in silicon, with an average readout fidelity of 82.9% at 3.3kHz measurement bandwidth. We use this technique to measure a triplet T_- to singlet S₀ relaxation time of 0.62ms in precision P-donor quantum dots. We also show that the use of RF readout does not impact the spin lifetimes (S₀ to T_- decay remained 2ms at zero detuning). This establishes single-gate sensing as a viable readout method for spin qubits.

[1] M. Veldhorst et al, Nature Communications 8, 1766 (2017).
[2] P. Pakkiam et al, Nano Letters 18, 40814085 (2018).
[3] E. T. Campbell et al, Nature 549, 172179 (2017).