Experimental investigation of the magnetic field driven superconductor/ insulator transition in underdoped $La_{2-x}Sr_xCuO_4$ thin films

TL;DR

This study investigates the magnetic field-induced superconductor-insulator transition in underdoped La2-xSrxCuO4 thin films, revealing quantum critical behavior and a complex phase diagram influenced by dimensional crossover.

Contribution

It provides new experimental evidence of quantum criticality and dimensional crossover in the superconductor-insulator transition of cuprate thin films.

Findings

Resistance plateaus indicate quantum critical behavior.

Scaling analysis supports the existence of a quantum critical point.

A comprehensive (H,x,T) phase diagram is proposed.

Abstract

The magnetic field driven superconductor/insulator transition is studied in a large variety of $La_{2-x}Sr_xCuO_4$ thin films of various Sr dopings. Temperature dependence of the resistivity down to 4.2 or 1.5 K under high pulsed magnetic field (up to 57 T) is analyzed. In particular, the existence of plateaus in the resistance versus temperature curves, in a limited range of temperature, for given values of the magnetic field is carefully investigated. It is shown to be associated to scaling behaviour of the resistance versus magnetic field curves, evocative of the presence of a quantum critical point. A three-dimensional (H,x,T) phase diagram is proposed, taking into account the intrinsic lamellar nature of the materials by the existence of a temperature crossover from quantum-two-dimensional to three-dimensional behavior.