近日，奥地利维也纳大学Arndt, Markus团队研究了纳米电机两种振动模式的量子基态冷却。2026年4月6日出版的《自然—物理学》杂志发表了这项成果。
在量子极限下控制纳米尺度物体的运动，为检验基础量子物理学以及推动量子传感的发展提供了机遇。其中，旋转运动尤其引人关注，因为其在紧凑的闭合构型空间中的非线性动力学行为，能够揭示旋转干涉、角构型之间的隧穿以及量子增强型扭矩传感等现象。此类实验的一个关键要求，是能够捕获纳米转子并将其取向冷却至接近二维摆动量子基态。当旋转运动被限制在简谐势阱中时，即表现为摆动运动。
研究组证明，通过向高精细度腔体内进行相干散射，能够实现对光悬浮SiO2纳米粒子的两个正交摆动模式的基态冷却。利用激光诱导解吸装载技术，研究组在短短一天内，成功捕获了数个二氧化硅纳米球二聚体和三聚体，并将其冷却至各自的基态。两个摆动自由度同时冷却，使研究组能够将单个纳米转子的取向相对于空间固定轴进行对准，其角精度优于20微弧度——这已接近量子力学的零点涨落极限。
附：英文原文
Title: Quantum ground-state cooling of two librational modes of a nanorotor
Author: Troyer, Stephan, Fechtel, Florian, Hummer, Lorenz, Rudolph, Henning, Stickler, Benjamin A., Deli, Uro, Arndt, Markus
Issue&Volume: 2026-04-06
Abstract: Controlling the motion of nanoscale objects at the quantum limit promises opportunities to test fundamental quantum physics and advances in quantum sensing. Rotational motion is of particular interest, as its nonlinear dynamics in a compact, closed configuration space provides access to phenomena such as rotational interferometry, tunnelling between angular configurations and quantum-enhanced torque sensing. A key requirement for such experiments is the capability to trap nanorotors and cool their orientation close to the two-dimensional librational quantum ground state. When rotational motion is confined in a harmonic potential, it becomes librational. Here we demonstrate that coherent scattering into a high-finesse cavity enables the ground-state cooling of two orthogonal librational modes of an optically levitated SiO2 nanoparticle. Using a laser-induced desorption loading technique, we trap and cool several dimers and trimers of silica nanospheres to their respective ground states, all within a single day. The simultaneous cooling of both librational degrees of freedom allows us to align an individual nanorotor with respect to a space-fixed axis with an angular precision better than 20μrad—close to the quantum-mechanical zero-point fluctuations.
DOI: 10.1038/s41567-026-03219-1
Source: https://www.nature.com/articles/s41567-026-03219-1