Surface-acoustic-wave resonators with Ti, Cr, and Au metallization on GaAs

Abstract

Surface-acoustic-wave (SAW) resonators, which confine SAW phonons in a small region between two Bragg reflectors, are attractive for studying the acoustic analog of cavity quantum electrodynamics. We have investigated characteristics of SAW resonators fabricated by patterning a metal film of Ti, Cr, and Au on GaAs and AlGaAs/GaAs heterostructure surfaces. The resonator modes and the acoustic band gap are identified by measuring the radio-frequency reflection spectrum and local piezoelectric potential with a quantum point contact. Ti metallization, showing a large band gap and small velocity modulation, is the best choice for designing a high-quality SAW resonator for GaAs.