Journal Article Enhanced electron-phonon coupling for a semiconductor charge qubit in a surface phonon cavity

CHEN, Jun  ,  Chen, Jun  ,  佐藤, 裕也  ,  Satou, Yuya  ,  小坂, 玲雄  ,  Kosaka, Reo  ,  橋坂, 昌幸  ,  Hashisaka, Masayuki  ,  村木, 康二  ,  Muraki, Koji  ,  藤澤, 利正  ,  Fujisawa, Toshimasa

5p.15176 , 2015-10 , Nature publishing group
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.

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