Doping-dependent competition between superconductivity and polycrystalline charge density waves

Abstract

From systematic analysis of the high pulsed magnetic field resistance data of La${}_{2-x}$Sr${}_x$CuO${}_4$ thin films, we extract an experimental phase diagram for several doping values ranging from the very underdoped to the very overdoped regimes. Our analysis highlights a competition between charge density waves and superconductivity which is ubiquitous between $x=0.08$ and $x=0.19$ and produces the previously observed double step transition. When suppressed by a strong magnetic field, superconductivity is resilient for two specific doping ranges centered around respectively $x\approx 0.09$ and $x\approx 0.19$ and the characteristic temperature for the onset of the competing charge density wave phase is found to vanish above $x=0.19$. At $x=1/8$ the two phases are found to coexist exactly at zero magnetic field.

13 figures. Changes from previous version are in red. A few clarifications and a discussion about the different materials were added together with additional references