What Makes Cuprate Superconductors so Exceptional?
Invited
Abstract
A comprehensive experiment will be decsribed in which over 2,000 single-crystal LSCO films were grown by molecular beam epitaxy and studied for 12 years. Resistivity, RH, magnetoresistance, Tc, penetration depth, and coherence length have been measured precisely as a function of temperature T (down to 300 mK), magnetic field B (up to 90 T), doping, and in-plane azimuth angle. [1-3]
The key findings are as follows. (i) The superconducting phase stiffness is extremely low, comparable to Tc. (ii) The superfluid density Ns(T) decreases linearly with T, up to Tc. (iii) Tc scales with Ns0 linearly but with an offset, except very close to the dome edges where it scales as √Ns0. (iv) The superconducting state develops from an electronic nematic state that breaks the C4 symmetry of the underlying crystal lattice. (v) The electron fluid behaves as if it were comprised of two components, one Fermi-liquid (FL) like and the other showing resistivity linear in T and B, diminishing with increased doping, and tracking the nematicity, Ns0, and Tc.
The related results of other groups show that the above appears to be typical of high-Tc cuprates and independent on the details of the Fermi surface, the number of CuO2 planes in the unit cell, the presence or absence of CuO chains, the density and the nature of dopants, the superconducting gap size, etc.
We conclude that high-Tc superconductivity in cuprates involves some new physics that entails strong pairing, strong electron correlations, strong thermal phase fluctuations, and strong pair-breaking, intrinsic but T- and doping-dependent.
References
[1] I. Bozovic, X. He, J. Wu and A. T. Bollinger, Nature 536, 309 (2016).
[2] J. Wu, A. T. Bollinger, X. He and I. Bozovic, Nature 547, 432 (2017).
[3] P. Girardo-Gallo et al., Science 361, 479 (2018).
The key findings are as follows. (i) The superconducting phase stiffness is extremely low, comparable to Tc. (ii) The superfluid density Ns(T) decreases linearly with T, up to Tc. (iii) Tc scales with Ns0 linearly but with an offset, except very close to the dome edges where it scales as √Ns0. (iv) The superconducting state develops from an electronic nematic state that breaks the C4 symmetry of the underlying crystal lattice. (v) The electron fluid behaves as if it were comprised of two components, one Fermi-liquid (FL) like and the other showing resistivity linear in T and B, diminishing with increased doping, and tracking the nematicity, Ns0, and Tc.
The related results of other groups show that the above appears to be typical of high-Tc cuprates and independent on the details of the Fermi surface, the number of CuO2 planes in the unit cell, the presence or absence of CuO chains, the density and the nature of dopants, the superconducting gap size, etc.
We conclude that high-Tc superconductivity in cuprates involves some new physics that entails strong pairing, strong electron correlations, strong thermal phase fluctuations, and strong pair-breaking, intrinsic but T- and doping-dependent.
References
[1] I. Bozovic, X. He, J. Wu and A. T. Bollinger, Nature 536, 309 (2016).
[2] J. Wu, A. T. Bollinger, X. He and I. Bozovic, Nature 547, 432 (2017).
[3] P. Girardo-Gallo et al., Science 361, 479 (2018).
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Presenters
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Ivan Bozovic
Condensed Matter and Materials Science, Brookhaven National Laboratory, Condensed Matter Physics & Materials Science, Brookhaven National Lab, Brookhaven National Laboratory, Upton, NY 11973, USA, Brookhaven National Laboratory and Yale University
Authors
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Ivan Bozovic
Condensed Matter and Materials Science, Brookhaven National Laboratory, Condensed Matter Physics & Materials Science, Brookhaven National Lab, Brookhaven National Laboratory, Upton, NY 11973, USA, Brookhaven National Laboratory and Yale University