ARC Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, St. Lucia, QLD 4072, Australia.
Sci Adv. 2023 May 24;9(21):eade3591. doi: 10.1126/sciadv.ade3591.
When confined within an optical cavity light can exert strong radiation pressure forces. Combined with dynamical backaction, this enables important processes, such as laser cooling, and applications ranging from precision sensors to quantum memories and interfaces. However, the magnitude of radiation pressure forces is constrained by the energy mismatch between photons and phonons. Here, we overcome this barrier using entropic forces arising from the absorption of light. We show that entropic forces can exceed the radiation pressure force by eight orders of magnitude and demonstrate this using a superfluid helium third-sound resonator. We develop a framework to engineer the dynamical backaction from entropic forces, applying it to achieve phonon lasing with a threshold three orders of magnitude lower than previous work. Our results present a pathway to exploit entropic forces in quantum devices and to study nonlinear fluid phenomena such as turbulence and solitons.
当光被限制在光学腔内时,它可以产生强大的辐射压力。结合动力学反作用,这使得一些重要的过程成为可能,如激光冷却,以及从精密传感器到量子存储器和接口等各种应用。然而,辐射压力的大小受到光子和声子之间能量失配的限制。在这里,我们利用光吸收产生的熵力克服了这一障碍。我们表明,熵力可以超过辐射压力力八个数量级,并使用超流氦三声谐振器证明了这一点。我们开发了一个工程熵力动力学反作用的框架,并应用它来实现比以前的工作低三个数量级的声子激光阈值。我们的结果为在量子器件中利用熵力以及研究诸如湍流和孤子等非线性流体现象提供了一种途径。