Suppressed Charge Dispersion via Resonant Tunneling in a Single-Channel Transmon

TL;DR

This paper demonstrates significant suppression of charge dispersion in a semiconductor-based transmon qubit by exploiting resonant tunneling in a quantum dot, supported by a quantitative theoretical model.

Contribution

It introduces a model for qubit dispersion at a single-channel resonance that aligns with experimental observations, advancing understanding of charge noise mitigation.

Findings

Charge dispersion is strongly suppressed at quantum dot resonances.

The developed model accurately predicts experimental data.

Resonant tunneling reduces charge noise in transmon qubits.

Abstract

We demonstrate strong suppression of charge dispersion in a semiconductor-based transmon qubit across Josephson resonances associated with a quantum dot in the junction. On resonance, dispersion is drastically reduced compared to conventional transmons with corresponding Josephson and charging energies. We develop a model of qubit dispersion for a single-channel resonance, which is in quantitative agreement with experimental data.