Surpassing Quantum Noise Limits with Nonlinear Amplification
Abstract
Linear quantum amplifiers are indispensable tools for quantum technologies, yet their performance is fundamentally limited by quantum noise, precluding any signal-to-noise ratio (SNR) enhancement unless supplemented by post-selection or non-classical resources. To surpass this limitation, we propose a nonlinear quantum amplification strategy that exploits the interplay between a gain-stabilized bright eigenmode of a coupled two-mode bosonic system and Kerr nonlinearity. We demonstrate that this interplay enables the signal gain to surpass the noise gain in a selected quadrature, leading to a net increase in the SNR beyond the quantum limits of conventional linear amplifiers. Our work thus establishes a novel nonlinear amplification paradigm capable of enhancing the SNR, with promising applications across quantum information processing, quantum communications, and quantum metrology.
Cite
@article{arxiv.2603.11574,
title = {Surpassing Quantum Noise Limits with Nonlinear Amplification},
author = {Ya-Long Ren and Rong-Teng Cao and Sheng-Li Ma and Ren Zhang and Fu-Li Li and Franco Nori and Peng-Bo Li},
journal= {arXiv preprint arXiv:2603.11574},
year = {2026}
}