Competing orders suppressed by disorder around a hidden quantum critical point in cuprate high Tc superconductors

Abstract

We report extensive muon spin rotation measurements on the lightly doped Y1-xCaxBa2Cu3O6+y compound, which allows us to disentangle the effect of disorder, controlled by random Ca2+ substitution, from that of mere doping. A 3D phase diagram of lightly doped cuprates is accurately drawn, showing that a thermally activated antiferromagnetic phase competes with superconductivity around a quantum critical point, hidden underneath a frozen insulating magnetic state. Disorder suppresses both competing order parameters and unveils the underlying frozen state. Doping and disorder destroy the activated magnetic phase along a line of first order phase transitions that ends at the critical point.

4 figures, v.2: new more intuitive 3D cuprate phase diagram

References in corpus (5)

• Disorder, Metal-Insulator crossover and Phase diagram in high-Tc cuprates
• Spin dynamics near the critical doping in weakly-superconducting underdoped YBa2Cu3O6.35 (Tc=18K)
• Evidence for Charge Glass-like Behavior in Lightly Doped La_{2-x}Sr_{x}CuO_{4} at Low Temperatures
• Universal doping dependence of the ground state staggered magnetization in cuprates
• Implication of the Mott-limit violation in high-Tc cuprates

Cited by in corpus (7)

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• Magnetic glassy phase in FeSeTe single crystals
• Magnetic phase diagram of La${}_{2-x}$Sr${}_x$CoO${}_4$ revised using muon-spin relaxation
• Dissipation signatures of the normal and superfluid phases in torsion pendulum experiments with 3He in aerogel
• Singling out the effect of quenched disorder in the phase diagram of cuprates