Field Dependence of the Josephson Plasma Resonance in Layered Superconductors with Alternating Junctions

TL;DR

This paper studies how the Josephson plasma resonance behaves in layered superconductors with alternating junctions under low magnetic fields, revealing linear decreases in current densities and plasma frequencies, and estimates the Josephson penetration length from optical data.

Contribution

It provides a theoretical analysis of the field dependence of Josephson plasma resonance in layered superconductors with alternating junctions and extracts key parameters from experimental data.

Findings

Current densities decrease linearly with magnetic field.

Squared plasma frequencies decrease linearly with magnetic field.

Josephson penetration length is approximately 1100 Å at 10 K.

Abstract

The Josephson plasma resonance in layered superconductors with alternating critical current densities is investigated in a low perpendicular magnetic field. In the vortex solid phase the current densities and the squared bare plasma frequencies decrease linearly with the magnetic field. Taking into account the coupling due to charge fluctuations on the layers, we extract from recent optical data for SmLa_{1-x} Sr_x CuO_{4-delta} the Josephson penetration length lambda_{ab} approximately 1100 A parallel to the layers at T=10 K.