Chen J C H, Sato Y, Kosaka R, Hashisaka M, Muraki K, Fujisawa T
Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, 152-8551, Japan.
NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, 243-0198, Japan.
Sci Rep. 2015 Oct 15;5:15176. doi: 10.1038/srep15176.
Electron-phonon coupling is a major decoherence mechanism, which often causes scattering and energy dissipation in semiconductor electronic systems. However, this electron-phonon coupling may be used in a positive way for reaching the strong or ultra-strong coupling regime in an acoustic version of the cavity quantum electrodynamic system. Here we propose and demonstrate a phonon cavity for surface acoustic waves, which is made of periodic metal fingers that constitute Bragg reflectors on a GaAs/AlGaAs heterostructure. Phonon band gap and cavity phonon modes are identified by frequency, time and spatially resolved measurements of the piezoelectric potential. Tunneling spectroscopy on a double quantum dot indicates the enhancement of phonon assisted transitions in a charge qubit. This encourages studying of acoustic cavity quantum electrodynamics with surface phonons.
电子 - 声子耦合是一种主要的退相干机制，它常常在半导体电子系统中引起散射和能量耗散。然而，这种电子 - 声子耦合可以以一种积极的方式用于在腔量子电动力学系统的声学版本中达到强耦合或超强耦合 regime。在这里，我们提出并展示了一种用于表面声波的声子腔，它由周期性金属指构成，这些金属指在GaAs/AlGaAs异质结构上构成布拉格反射器。通过对压电势进行频率、时间和空间分辨测量来识别声子带隙和腔声子模式。对双量子点的隧穿光谱表明，电荷量子比特中声子辅助跃迁得到增强。这鼓励了对利用表面声子的声学腔量子电动力学的研究。
