Combining n-MOS Charge Sensing with p-MOS Silicon Hole Double Quantum Dots in a CMOS platform

TL;DR

This paper presents a CMOS-based ambipolar device integrating electron charge sensing with p-MOS hole double quantum dots, demonstrating tunable coupling, spin control, and relaxation measurements to advance hole spin-qubit technology.

Contribution

It introduces a novel CMOS platform with integrated charge sensing and control for hole quantum dots, addressing key challenges in hole spin-qubit development.

Findings

Achieved tunable inter-dot coupling over two orders of magnitude.

Demonstrated electric dipole spin resonance (EDSR) control of hole spins.

Measured hole singlet-triplet relaxation time of 11 microseconds.

Abstract

Holes in silicon quantum dots are receiving significant attention due to their potential as fast, tunable, and scalable qubits in semiconductor quantum circuits. Despite this, challenges remain in this material system including difficulties using charge sensing to determine the number of holes in a quantum dot, and in controlling the coupling between adjacent quantum dots. In this work, we address these problems by fabricating an ambipolar complementary metal-oxide-semiconductor (CMOS) device using multilayer palladium gates. The device consists of an electron charge sensor adjacent to a hole double quantum dot. We demonstrate control of the spin state via electric dipole spin resonance (EDSR). We achieve smooth control of the inter-dot coupling rate over two orders of magnitude and use the charge sensor to perform spin-to-charge conversion to measure the hole singlet-triplet relaxation time of 11 {\mu}s for a known hole occupation. These results provide a path towards improving the quality and controllability of hole spin-qubits.