Single shot latched readout of a quantum dot qubit using barrier gate pulsing

Abstract

Qubit latching techniques require precise tuning of multiple tunnel rates, which can be challenging when a qubit is coupled to a single reservoir. Here, we present such a method for single-shot measurement, in which the barrier gate is pulsed to dynamically control qubit-to-reservoir tunnel rates. We use it to reduce the qubit reset time in measurements of coherent Larmor oscillations of a Si/SiGe quantum dot hybrid qubit. The method is also readily applicable to other types of spin-based qubits.