An in-situ tunable radio-frequency quantum point contact

TL;DR

This paper introduces an in-situ tunable RF quantum point contact using a variable capacitance diode, enhancing its versatility as a fast charge sensor and applicable to various RF-detection schemes.

Contribution

It presents a novel method for in-situ tuning of RF quantum point contacts, improving their adaptability and performance in quantum charge detection.

Findings

Enhanced tuning of RF quantum point contact resonance frequency.

Improved charge detection speed and versatility.

Applicable to RF-SET and other RF-detection schemes.

Abstract

Incorporating a variable capacitance diode into a radio-frequency matching circuit allows us to in-situ tune the resonance frequency of an RF quantum point contact, increasing the versatility of the latter as a fast charge sensor of a proximal quantum circuit. The performance of this method is compared in detail to conventional low-frequency charge detection. The approach is also applicable to other RF-detection schemes, such as RF-SET circuits.