Fractional giant Shapiro resonances in frustrated systems driven by a time-dependent flux

Department of Physics and Center for Theoretical Physics, Seoul National University - Seoul 151-742, Korea

Received: 26 March 1996
Accepted: 3 July 1996

Abstract

We examine the response of a two-dimensional cylindrical array of Josephson junctions to a time-dependent Aharonov-Bohm flux, which can be mapped to tight-binding electrons in the same geometry. It is shown that a non-vanishing time-average of the persistent current is developed whenever the dc component of the flux is properly quantized, leading to giant Shapiro resonances. Here a perpendicular magnetic field is found to yield novel fractional resonances in addition to the integer ones. In particular, the topological origin of such integer and fractional quantization is pointed out.