Shapiro step at nonequilibrium conditions

¹ BLTP, JINR - Dubna, Moscow Region, 141980, Russia
² State University of Nature, Society and Man “Dubna” - Dubna, Moscow region, 141980, Russia
³ Department of Physics, Cairo University - Cairo, Egypt
⁴ Department of Physics, Faculty of Science, Menoufiya University - Menoufiya, Egypt

Received: 19 March 2016
Accepted: 25 July 2016

Abstract

Detailed numerical simulations of intrinsic Josephson junctions of high-temperature superconductors under external electromagnetic radiation are performed taking into account a charge imbalance effect. We demonstrate that the charge imbalance is responsible for a slope in the Shapiro step in the IV-characteristic. The value of slope increases with a nonequilibrium parameter. Coupling between junctions leads to the distribution of the slope's values along the stack. The nonperiodic boundary conditions shift the Shapiro step from the canonical position determined by , where f is a frequency of external radiation. This fact makes the interpretation of the experimentally found Shapiro step shift by the charge imbalance effect ambiguous.