Anderson-Higgs amplitude mode in Josephson junctions

Abstract

The Anderson-Higgs mode in a superconductor corresponds to a collective and coherent oscillation of the order parameter amplitude. We propose to detect this mode in a tunnel Josephson junction between two singlet s-wave diffusive superconductors. We find a strong enhancement of the tunneling current when the junction is pumped at the equilibrium gap frequency, corresponding to the activation of the Anderson-Higgs mode. By solving the Keldysh-Usadel equations, we obtain current peaks at specific bias voltages that can serve as signatures of the Anderson-Higgs mode.

11 pages, 6 figures