The Inductive Single-Electron Transistor (L-SET)

TL;DR

This paper presents a highly sensitive charge detection method using radio-frequency readout of a superconducting single-electron transistor's Josephson inductance, achieving low dissipation and promising near-quantum-limited energy sensitivity.

Contribution

It introduces a novel reactive readout technique for the single-electron transistor that significantly reduces dissipation and enhances charge sensitivity.

Findings

Charge sensitivity of 1.4 x 10^{-4} e/√Hz achieved

Reactive readout reduces dissipation by over two orders of magnitude

Potential for energy sensitivity below ħ with optimized design

Abstract

We demonstrate a sensitive method of charge detection based on radio-frequency readout of the Josephson inductance of a superconducting single-electron transistor. Charge sensitivity $1.4 \times 10^{-4}e/\sqrt{Hz}$, limited by preamplifier, is achieved in an operation mode which takes advantage of the nonlinearity of the Josephson potential. Owing to reactive readout, our setup has more than two orders of magnitude lower dissipation than the existing method of radio-frequency electrometry. With an optimized sample, we expect uncoupled energy sensitivity below $\hbar$ in the same experimental scheme.