Josephson junction microwave amplifier in self-organized noise compression mode

TL;DR

This paper presents a novel Josephson junction microwave amplifier that achieves near-quantum-limited noise performance through self-organized noise compression, offering potential for wide bandwidth applications.

Contribution

Introduces a new amplifier based on negative resistance of a damped Josephson junction, demonstrating near-quantum-limited noise performance via self-organization.

Findings

Achieves noise temperature of about 3.2 times the quantum limit at 2.8 GHz

Utilizes negative resistance and self-organization for noise reduction

Potential for wide bandwidth operation demonstrated through simulations

Abstract

The fundamental noise limit of a phase-preserving amplifier at frequency $\omega /2\pi $ is the standard quantum limit $T_{q}=\hbar \omega /2k_{B}$. In the microwave range, the best candidates have been amplifiers based on superconducting quantum interference devices (reaching the noise temperature $T_{n} \sim 1.8 T_{q}$ at 700 MHz), and non-degenerate parametric amplifiers (reaching noise levels close to the quantum limit $T_{n}\approx T_{q}$ at 8 GHz). We introduce a new type of an amplifier based on the negative resistance of a selectively damped Josephson junction. Noise performance of our amplifier is limited by mixing of quantum noise from Josephson oscillation regime down to the signal frequency. Measurements yield nearly quantum-limited operation, $T_{n}=(3.2\pm 1.0) T_{q}$ at 2.8 GHz, owing to self-organization of the working point. Simulations describe the characteristics of our device well and indicate potential for wide bandwidth operation.