最近，瑞士苏黎世联邦理工学院的Lukas Novotny研究团队提出了悬浮纳米粒子两种机械模式的同步基态冷却。相关成果已于2023年3月6日在国际权威学术期刊《自然—物理学》上发表。
该研究团队演示了光学悬浮纳米颗粒的二维基态冷却。研究人员利用相干散射到光学空腔模式，他们分别将两个独立质心模式的占有数减少到0.83和0.81。通过控制纳米粒子机械模式的频率分离和空腔耦合强度，他们展示了从一维到二维基态冷却的过渡。这种二维控制为旋转传感的量子限制轨道角动量态奠定了基础，并结合前面的沿第三运动轴的基态冷却，可以对大质量物体进行完整的三维基态冷却。
据了解，大质量机械系统的量子基态是研究宏观量子态和构建高保真传感器的基石。随着单运动模式基态冷却的最新突破，悬浮纳米粒子进入了量子领域。为了克服有害的交叉耦合和退相干效应，量子控制需要扩展到更多的系统维度，但迄今为止，一个脱耦的暗模式效应阻碍了基于空腔的多个机械模式的基态冷却。
附：英文原文
Title: Simultaneous ground-state cooling of two mechanical modes of a levitated nanoparticle
Author: Piotrowski, Johannes, Windey, Dominik, Vijayan, Jayadev, Gonzalez-Ballestero, Carlos, de los Ros Sommer, Andrs, Meyer, Nadine, Quidant, Romain, Romero-Isart, Oriol, Reimann, Ren, Novotny, Lukas
Issue&Volume: 2023-03-06
Abstract: The quantum ground state of a massive mechanical system is a stepping stone for investigating macroscopic quantum states and building high fidelity sensors. With the recent achievement of ground-state cooling of a single motional mode, levitated nanoparticles have entered the quantum domain. To overcome detrimental cross-coupling and decoherence effects, quantum control needs to be expanded to more system dimensions, but the effect of a decoupled dark mode has so far hindered cavity-based ground-state cooling of multiple mechanical modes. Here, we demonstrate two-dimensional ground-state cooling of an optically levitated nanoparticle. Utilizing coherent scattering into an optical cavity mode, we reduce the occupation numbers of two separate centre-of-mass modes to 0.83 and 0.81, respectively. By controlling the frequency separation and the cavity coupling strengths of the nanoparticle’s mechanical modes, we show the transition from 1D to 2D ground-state cooling. This 2D control lays the foundations for quantum-limited orbital angular momentum states for rotation sensing and, combined with ground-state cooling along the third motional axis shown previously, may allow full 3D ground-state cooling of a massive object.
DOI: 10.1038/s41567-023-01956-1
Source: https://www.nature.com/articles/s41567-023-01956-1