Asjad M, Li Jie, Zhu Shi-Yao, You J Q
Department of Applied Mathematics and Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates.
Interdisciplinary Center of Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, China.
Fundam Res. 2022 Jul 23;3(1):3-7. doi: 10.1016/j.fmre.2022.07.006. eCollection 2023 Jan.
Cavity magnomechanics has recently become a new platform for studying macroscopic quantum phenomena. The magnetostriction induced vibration mode of a large-size ferromagnet or ferrimagnet reaching its ground state represents a genuine macroscopic quantum state. Here we study the ground-state cooling of the mechanical vibration mode in a cavity magnomechanical system, and focus on the role of magnon squeezing in improving the cooling efficiency. The magnon squeezing is obtained by exploiting the magnon self-Kerr nonlinearity. We find that the magnon squeezing can significantly and even completely suppress the magnomechanical Stokes scattering. It thus becomes particularly useful in realizing ground-state cooling in the unresolved-sideband regime, where the conventional sideband cooling protocols become inefficient. We also find that the coupling to the microwave cavity plays only an adverse effect in mechanical cooling. This makes essentially the two-mode magnomechanical system (without involving the microwave cavity) a preferred system for cooling the mechanical motion, in which the magnon mode is established by a uniform bias magnetic field and a microwave drive field.
腔磁机械学最近已成为研究宏观量子现象的一个新平台。大尺寸铁磁体或亚铁磁体达到其基态时的磁致伸缩诱导振动模式代表一种真正的宏观量子态。在此，我们研究腔磁机械系统中机械振动模式的基态冷却，并着重探讨磁子压缩在提高冷却效率方面的作用。磁子压缩是通过利用磁子自克尔非线性效应获得的。我们发现，磁子压缩能够显著甚至完全抑制磁机械斯托克斯散射。因此，它在未分辨边带区域实现基态冷却时变得尤为有用，在该区域传统的边带冷却方案效率低下。我们还发现，与微波腔的耦合在机械冷却中仅起不利作用。这使得本质上的双模磁机械系统（不涉及微波腔）成为冷却机械运动的首选系统，其中磁子模式由均匀偏置磁场和微波驱动场建立。
