Dispersively probed microwave spectroscopy of a silicon hole double quantum dot

TL;DR

This paper introduces a dispersively probed microwave spectroscopy method for silicon hole double quantum dots, enabling detailed spin-dependent energy-level analysis crucial for scalable quantum computing architectures.

Contribution

It presents a novel two-tone spectroscopy technique compatible with scalable silicon quantum dot devices, providing detailed spin and energy-level information.

Findings

Measured g-factors and spin-orbit couplings for silicon hole quantum dots.

Demonstrated dispersive readout via rf-gate reflectometry.

Compared experimental data with Jaynes-Cummings model predictions.

Abstract

Owing to ever increasing gate fidelities and to a potential transferability to industrial CMOS technology, silicon spin qubits have become a compelling option in the strive for quantum computation. In a scalable architecture, each spin qubit will have to be finely tuned and its operating conditions accurately determined. In this prospect, spectroscopic tools compatible with a scalable device layout are of primary importance. Here we report a two-tone spectroscopy technique providing access to the spin-dependent energy-level spectrum of a hole double quantum dot defined in a split-gate silicon device. A first GHz-frequency tone drives electric-dipole spin resonance enabled by the valence-band spin-orbit coupling. A second lower-frequency tone (approximately 500 MHz) allows for dispersive readout via rf-gate reflectometry. We compare the measured dispersive response to the linear response calculated in an extended Jaynes-Cummings model and we obtain characteristic parameters such as g-factors and tunnel/spin-orbit couplings for both even and odd occupation.