Studies of h/e Aharonov-Bohm Photovoltaic Oscillations in Mesoscopic Au Rings

TL;DR

This study investigates microwave-induced photovoltaic oscillations in mesoscopic gold rings, revealing how microwave intensity and temperature affect electron phase coherence and PV oscillation behavior.

Contribution

It provides experimental evidence of h/e Aharonov-Bohm PV oscillations in Au rings and explores how microwave radiation influences electron phase coherence.

Findings

h/e PV oscillations observed at low microwave intensities

Microwave radiation quenches PV oscillations at moderate intensities

Temperature dependence indicates microwave-induced dephasing

Abstract

We have investigated a mesoscopic photovoltaic (PV) effect in micron-size Au rings in which a dc voltage Vdc is generated in response to microwave radiation. The effect is due to the lack of inversion symmetry in a disordered system. Aharonov-Bohm PV oscillations with flux period h/e have been observed at low microwave intensities for temperatures ranging from 1.4 to 13 K. For moderate microwave intensities the h/e PV oscillations are completely quenched providing evidence that the microwaves act to randomize the phase of the electrons. Studies of the temperature dependence of Vdc also provide evidence of the dephasing nature of the microwave field. A complete theoretical explanation of the observed behavior seems to require a theory for the PV effect in a ring geometry.