Applied Physics Letters

Parametric amplification via coupling linear and nonlinear superconducting resonators

Yapeng Lu, Weiwei Xu, Guozhu Sun, Peiheng Wu

Published Sep 15, 2025• 1 citation

Abstract

We experimentally demonstrate a coupled superconducting resonator system in which a superconducting quantum interference device (SQUID) modulated nonlinear resonator is capacitively coupled to a fixed-frequency linear resonator. This configuration enables flux-tunable mode separation and parametric interactions between spatially separated modes. By exploiting the SQUID-induced nonlinearity, we achieve both single-mode (degenerate) and two-mode (nondegenerate) parametric amplification via three-wave mixing processes. Gains exceeding 15 dB are obtained in both the tunable resonator and the fixed frequency linear resonator with near quantum limit noise performance. Our device may provide an attractive solution for storing and releasing squeezed photons.

DOI: 10.1063/5.0268687

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