An Infrared study of the Josephson vortex state in high-Tc cuprates

TL;DR

This study uses c-axis infrared spectroscopy to examine the Josephson vortex state in high-Tc cuprates, revealing magnetic field effects on superfluid density that challenge existing theoretical models.

Contribution

It provides experimental insights into the Josephson vortex state in high-Tc cuprates and highlights discrepancies with current theoretical descriptions.

Findings

Superfluid density decreases significantly with magnetic field in La_{2-x} Sr_x CuO_4

Existing models do not fully explain the observed suppression effects

Results suggest need for revised theories of vortex states in high-Tc superconductors

Abstract

We report the results of the c-axis infrared spectroscopy of La_{2-x} Sr_x CuO_4 in high magnetic field oriented parallel to the CuO_2 planes. A significant suppression of the superfluid density with magnetic field rho_s(H) is observed for both underdoped (x=0.125) and overdoped (x=0.17) samples. We show that the existing theoretical models of the Josephson vortex state fail to consistently describe the observed effects and discuss possible reasons for the discrepancies.