Gate-reflectometry dispersive readout and coherent control of a spin qubit in silicon

Abstract

Silicon spin qubits have emerged as a promising path to large-scale quantum processors. In this prospect, the development of scalable qubit readout schemes involving a minimal device overhead is a compelling step. Here we report the implementation of gate-coupled rf reflectometry for the dispersive readout of a fully functional spin qubit device. We use a p-type double-gate transistor made using industry-standard silicon technology. The first gate confines a hole quantum dot encoding the spin qubit, the second one a helper dot enabling readout. The qubit state is measured through the phase response of a lumped-element resonator to spin-selective interdot tunneling. The demonstrated qubit readout scheme requires no coupling to a Fermi reservoir, thereby offering a compact and potentially scalable solution whose operation may be extended above 1 K.

Abstract

Gate-reflectometry is a recently demonstrated measurement technique for single spin states in silicon. It is potentially able to perform quantum non-demolition measurements and uses compact circuitry that can be scaled up to larger quantum computers. Crippa et al. successfully combine gate-reflectometry qubit readout and coherent control.