Charge density wave fluctuations in La2-xSrxCuO4 and their competition with superconductivity

TL;DR

This study uses x-ray diffraction to investigate charge-density-wave order in La2-xSrxCuO4, revealing its competition with superconductivity and coexistence with magnetic order, with detailed phase diagram insights.

Contribution

It provides detailed measurements of CDW order parameters and their relationship with magnetic order and superconductivity in La2-xSrxCuO4.

Findings

CDW order appears with onset temperatures 51-80 K

CDW is strongest near 1/8 doping

CDW is suppressed in the superconducting state

Abstract

We report hard (14 keV) x-ray diffraction measurements on three compositions (x=0.11,0.12,0.13) of the high-temperature superconductor La2-xSrxCuO4. All samples show charge-density-wave (CDW) order with onset temperatures in the range 51-80 K and ordering wavevectors close to (0.23,0,0.5). The CDW is strongest with the longest in-plane correlation length near 1/8 doping. On entering the superconducting state the CDW is suppressed, demonstrating the strong competition between the charge order and superconductivity. CDW order coexists with incommensurate magnetic order and wavevectors of the two modulations have the simple relationship $\delta_{charge}= 2\delta_{spin}$. The intensity of the CDW Bragg peak tracks the intensity of the low-energy (quasi-elastic) spin fluctuations. We present a phase diagram of La2-xSrxCuO4 including the pseudogap phase, CDW and magnetic order.