近日，瑞士苏黎世联邦理工学院Frimmer, Martin团队研究了室温下的高纯度量子光力学。相关论文发表在2025年8月6日出版的《自然—物理学》杂志上。

利用机械振荡器中的量子效应，如反作用力规避测量或机械自由度的压缩，需要在高纯度量子态下制备振荡器。迄今为止，光力学中最大的状态纯度已经通过昂贵的低温冷却结合耦合到由相干辐射场驱动的电磁谐振器来实现。

研究组将相干散射放入法布里-帕姆罗特腔中，将光学悬浮二氧化硅纳米粒子的兆赫频率振动模式从室温冷却到量子基态。研究组利用边带测温技术推断出在最佳条件下声子居数为0.04量子，对应于92%的状态纯度。他们的室温实验纯度超过了机械箝位振荡器在低温环境下提供的性能，为室温下的高纯度量子光力学建立了平台。

附：英文原文

Title: High-purity quantum optomechanics at room temperature

Author: Dania, Lorenzo, Kremer, Oscar Schmitt, Piotrowski, Johannes, Candoli, Davide, Vijayan, Jayadev, Romero-Isart, Oriol, Gonzalez-Ballestero, Carlos, Novotny, Lukas, Frimmer, Martin

Issue&Volume: 2025-08-06

Abstract: Exploiting quantum effects in a mechanical oscillator, such as back-action-evading measurements or squeezing of the mechanical degrees of freedom, requires the oscillator to be prepared in a high-purity quantum state. The largest state purities in optomechanics to date have been achieved with costly cryogenic cooling combined with coupling to electromagnetic resonators driven with a coherent radiation field. Here we use coherent scattering into a Fabry–Pérot cavity to cool the megahertz-frequency librational mode of an optically levitated silica nanoparticle from room temperature to its quantum ground state. We use sideband thermometry to infer a phonon population of 0.04 quanta under optimal conditions, corresponding to a state purity of 92%. The purity reached by our room-temperature experiment exceeds the performance offered by mechanically clamped oscillators in a cryogenic environment, establishing a platform for high-purity quantum optomechanics at room temperature.

DOI: 10.1038/s41567-025-02976-9

Source: https://www.nature.com/articles/s41567-025-02976-9