title: Enhanced electron-phonon coupling for a semiconductor charge qubit in a surface phonon cavity.
abstract: 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.
authors.affiliation: Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, 152-8551, Japan.
authors.forename: J C H
authors.initials: JC
authors.lastname: Chen
authors.affiliation: Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, 152-8551, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, 152-8551, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Kosaka
authors.affiliation: Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, 152-8551, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hashisaka
authors.affiliation: NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, 243-0198, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Muraki
authors.affiliation: Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, 152-8551, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fujisawa