Low temperature superfluid stiffness of d-wave superconductor in a magnetic field

TL;DR

This paper investigates how the superfluid density in a d-wave superconductor varies with temperature and magnetic field, revealing a crossover from linear to quadratic temperature dependence at low temperatures.

Contribution

It provides a microscopic calculation of superfluid density in the vortex state, highlighting a distinct temperature dependence crossover not previously detailed.

Findings

Superfluid density shows a linear to quadratic temperature dependence crossover below T* ∝ √H.

The crossover behavior differs from the effective penetration depth's temperature dependence.

Proposes experimental detection via mutual-inductance measurements.

Abstract

The temperature and field dependence of the superfluid density $\rho_s$ in the vortex state of a d-wave superconductor are calculated using a microscopic model in the quasiclassical approximation. We show that at temperatures below T^{*} \varpropto \sqrt{H}$, the linear T dependence of rho_s crosses over to a T^2 dependence differently from the behavior of the effective penetration depth, lambda_eff^{-2}(T). We point out that the expected dependences could be probed by a mutual-inductance technique experiment.