Single-shot single-gate RF spin readout in silicon
Abstract
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 3.3~kHz measurement bandwidth. We use this technique to measure a triplet T- to singlet S0 relaxation time of 0.62~ms 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 2~ms. This establishes single-gate sensing as a viable readout method for spin qubits.