Quantum Dot-Based Parametric Amplifiers

TL;DR

This paper introduces a novel quantum dot-based parametric amplifier leveraging quantum capacitance for non-linear amplification, demonstrating phase-sensitive gain in a CMOS nanowire device with potential advantages over traditional JPAs.

Contribution

It proposes and experimentally demonstrates a quantum dot-based parametric amplifier using quantum capacitance, offering an alternative to Josephson-based amplifiers with promising performance and integration benefits.

Findings

Achieved phase-sensitive parametric gain of -3 to +3 dB.

Demonstrated operation at 1.8 GHz in a CMOS nanowire device.

Model predicts comparable gains and bandwidths to JPAs with current technology.

Abstract

Josephson parametric amplifiers (JPAs) approaching quantum-limited noise performance have been instrumental in enabling high fidelity readout of superconducting qubits and, recently, semiconductor quantum dots (QDs). We propose that the quantum capacitance arising in electronic two-level systems (the dual of Josephson inductance) can provide an alternative dissipation-less non-linear element for parametric amplification. We experimentally demonstrate phase-sensitive parametric amplification using a QD-reservoir electron transition in a CMOS nanowire split-gate transistor embedded in a 1.8~GHz superconducting lumped-element microwave cavity, achieving parametric gains of -3 to +3 dB, limited by Sisyphus dissipation. Using a semi-classical model, we find an optimised design within current technological capabilities could achieve gains and bandwidths comparable to JPAs, while providing complementary specifications with respect to integration in semiconductor platforms or operation at higher magnetic fields.