  Phase-coherent acoustoelectric transport is reported.Aharonov-Bohm
oscillations in the acoustoelectric current with visibility exceeding 100% were
observed in mesoscopic GaAs rings as a function of an external magnetic field
at cryogenic temperatures. A theoretical analysis of the acoustoelectric
transport in ballistic devices is proposed to model experimental observations.
Our findings highlight a close analogy between acoustoelectric transport and
thermoelectric properties in ballistic devices.
