Reduction of Dissipative Nonlinear Conductivity of Superconductors by Static and Microwave Magnetic Fields
Reduction of Dissipative Nonlinear Conductivity of Superconductors by Static and Microwave Magnetic Fields
A theory of dissipative nonlinear conductivity, $\sigma_1(\omega,H)$, of s-wave superconductors under strong electromagnetic fields at low temperatures is proposed. Closed-form expressions for $\sigma_1(H)$ and the surface resistance $R_s(\omega,H)$ are obtained in the nonequilibrium dirty limit for which $\sigma_1(H)$ has a significant minimum as a function of a low-frequency $(\hbar\omega\ll k_BT)$ …