Spin-liquid model of the sharp resistivity drop in $La_{1.85}Ba_{0.125}CuO_4$

TL;DR

This paper applies a phenomenological model to analyze how magnetic fields affect the onset temperature of fluctuating superconductivity in La-based cuprates, explaining experimental observations of resistivity drops.

Contribution

It extends a previous model to quantitatively match recent measurements of the magnetic field dependence of superconducting fluctuations in La_{1.85}Ba_{0.125}CuO_4.

Findings

The slope of T**(H) decreases with increasing H.

The upper critical field increases as temperature decreases.

Quantitative agreement with experimental data is achieved.

Abstract

We use the phenomenological model proposed in our previous paper [Phys. Rev. Lett. {\bf 98}, 237001 (2007)] to analyse the magnetic field dependence of the onset temperature for two-dimensional fluctuating superconductivity $T^{**} (H)$. We demonstrate that the slope of $T^{**} (H)$ progressively goes down as $H$ increases, such that the upper critical field progressively increases as $T$ decreases. The quantitative agreement with the recent measurements of $T^{**} (H)$ in $La_{1.85}Ba_{0.125}CuO_4$ is achieved for the same parameter value as was derived in our previous publication from the analysis of the electron self energy.