Universal Critical Quantum Properties of Cuprate Superconductors
T. Schneider
IBM Research Division, Zurich Research Laboratory Säumerstr. 4, 8803 Rüschlikon, Switzerland
and Physik-Institut, University of Zürich, 8057 Zürich, Switzerland
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Using the scaling theory of quantum critical phenomena we explore the occurrence of universal critical behavior at the insulator-to-superconductor and superconductor-to-normal state transitions at zero temperature. Experimentally, these phase transitions are driven by doping and correspond to critical end points of the phase transition line in the temperature-hole concentration plane. Provided that the order parameter is a complex scalar in two dimensions, and that the London relation between superfluid number density and magnetic penetration depth holds, the scaling theory predicts universal behavior close to the insulator-to-superconductor transition. In particular, transition temperature and zero temperature penetration depth are universally related and the sheet resistance adopts a universal value. These predictions agree remarkably well with available experimental data and provide useful constraints for a microscopic theory.
DOI: 10.12693/APhysPolA.91.203
PACS numbers: 74.72.-h, 74.25.-q, 74.62.-c, 74.62.Dh