Chang Haonan, Li Zhenyao, Lou Wenkai, Yao Qifeng, Lai Jia-Min, Liu Bing, Ni Haiqiao, Niu Zhichuan, Chang Kai, Zhang Jun
State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Nanoscale. 2022 Sep 22;14(36):13046-13052. doi: 10.1039/d2nr03376c.
Cavity optomechanical systems operating at the quantum ground state provide a novel way for the ultrasensitive measurement of mass and displacement and provide a new toolbox for emerging quantum information technologies. The high-frequency optomechanical devices could reach the quantum ground state at a high temperature because the access to high frequency is favorable for the cavity optomechanical devices to decouple from the thermal environment. However, reaching ultra-high frequency (THz) is extremely difficult due to the structure of cavity optomechanical devices and properties of materials. In this paper, by introducing acoustic topological interface states, we designed a THz mechanical frequency semiconductor pillar microcavity optomechanical device based on a GaAs/AlAs nanophononic superlattice. In the optomechanical system, multi-optical cavity modes are obtained and the frequency separation between adjacent optical modes is equal to the frequency of the mechanical mode (optomechanical frequency matching). By detuning the laser pump to a lower (higher) energy-resolved sideband to make a spontaneously scattering photon doubly resonate with optical cavity modes at an anti-Stokes (Stokes) frequency and pump frequency, we can achieve an anti-Stokes (Stokes) scattering efficiency 2600 (1800) times larger than that of Stokes (anti-Stokes) scattering, which provides potential for laser cooling and low threshold phonon lasing in the optomechanical system.
工作在量子基态的腔光机械系统为质量和位移的超灵敏测量提供了一种新方法，并为新兴的量子信息技术提供了一个新的工具箱。高频光机械器件能够在高温下达到量子基态，因为进入高频有利于腔光机械器件与热环境解耦。然而，由于腔光机械器件的结构和材料特性，达到超高频率（太赫兹）极其困难。在本文中，通过引入声学拓扑界面态，我们基于GaAs/AlAs纳米声子超晶格设计了一种太赫兹机械频率半导体柱微腔光机械器件。在该光机械系统中，获得了多个光学腔模，相邻光学模之间的频率间隔等于机械模的频率（光机械频率匹配）。通过将激光泵浦失谐到较低（较高）的能量分辨边带，使一个自发散射光子在反斯托克斯（斯托克斯）频率和泵浦频率下与光学腔模发生双共振，我们可以实现比斯托克斯（反斯托克斯）散射大2600（1800）倍的反斯托克斯（斯托克斯）散射效率，这为光机械系统中的激光冷却和低阈值声子激光提供了潜力。
