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Title: Temperature-Dependent Ellipsometry Measurements of Partial Coulomb Energy in Superconducting Cuprates

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Center for Emergent Superconductivity (CES)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1388857
DOE Contract Number:
AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. X; Journal Volume: 6; Journal Issue: 3; Related Information: CES partners with Brookhaven National Laboratory (BNL); Argonne National Laboratory; University of Illinois, Urbana-Champaign; Los Alamos National Laboratory
Country of Publication:
United States
Language:
English
Subject:
phonons, thermal conductivity, energy storage (including batteries and capacitors), superconductivity, defects, spin dynamics

Citation Formats

Levallois, J., Tran, M. K., Pouliot, D., Presura, C. N., Greene, L. H., Eckstein, J. N., Uccelli, J., Giannini, E., Gu, G. D., Leggett, A. J., and van der Marel, D. Temperature-Dependent Ellipsometry Measurements of Partial Coulomb Energy in Superconducting Cuprates. United States: N. p., 2016. Web. doi:10.1103/PhysRevX.6.031027.
Levallois, J., Tran, M. K., Pouliot, D., Presura, C. N., Greene, L. H., Eckstein, J. N., Uccelli, J., Giannini, E., Gu, G. D., Leggett, A. J., & van der Marel, D. Temperature-Dependent Ellipsometry Measurements of Partial Coulomb Energy in Superconducting Cuprates. United States. doi:10.1103/PhysRevX.6.031027.
Levallois, J., Tran, M. K., Pouliot, D., Presura, C. N., Greene, L. H., Eckstein, J. N., Uccelli, J., Giannini, E., Gu, G. D., Leggett, A. J., and van der Marel, D. 2016. "Temperature-Dependent Ellipsometry Measurements of Partial Coulomb Energy in Superconducting Cuprates". United States. doi:10.1103/PhysRevX.6.031027.
@article{osti_1388857,
title = {Temperature-Dependent Ellipsometry Measurements of Partial Coulomb Energy in Superconducting Cuprates},
author = {Levallois, J. and Tran, M. K. and Pouliot, D. and Presura, C. N. and Greene, L. H. and Eckstein, J. N. and Uccelli, J. and Giannini, E. and Gu, G. D. and Leggett, A. J. and van der Marel, D.},
abstractNote = {},
doi = {10.1103/PhysRevX.6.031027},
journal = {Physical Review. X},
number = 3,
volume = 6,
place = {United States},
year = 2016,
month = 8
}
  • Here we performed an experimental study of the temperature and doping dependence of the energy-loss function of the bilayer and trilayer bismuth cuprates family. The primary aim is to obtain information on the energy stored in the Coulomb interaction between the conduction electrons, on the temperature dependence thereof, and on the change of Coulomb interaction when Cooper pairs are formed. We performed temperature-dependent ellipsometry measurements on several Bi 2Sr 2CaCu 2O 8₋x single crystals: underdoped with T c=60, 70, and 83 K; optimally doped with T c=91 K; overdoped with T c=84, 81, 70, and 58 K; as well asmore » optimally doped Bi 2Sr 2Ca 2Cu 3O 10+x with T c=110 K. Our first observation is that, as the temperature drops through T c, the loss function in the range up to 2 eV displays a change of temperature dependence as compared to the temperature dependence in the normal state. This effect at—or close to—T c depends strongly on doping, with a sign change for weak overdoping. The size of the observed change in Coulomb energy, using an extrapolation with reasonable assumptions about its q dependence, is about the same size as the condensation energy that has been measured in these compounds. Our results therefore lend support to the notion that the Coulomb energy is an important factor for stabilizing the superconducting phase. Lastly, because of the restriction to small momentum, our observations do not exclude a possible significant contribution to the condensation energy of the Coulomb energy associated with the region of q around (π,π).« less
    Cited by 1
  • Here we performed an experimental study of the temperature and doping dependence of the energy-loss function of the bilayer and trilayer bismuth cuprates family. The primary aim is to obtain information on the energy stored in the Coulomb interaction between the conduction electrons, on the temperature dependence thereof, and on the change of Coulomb interaction when Cooper pairs are formed. We performed temperature-dependent ellipsometry measurements on several Bi 2Sr 2CaCu 2O 8₋x single crystals: underdoped with T c=60, 70, and 83 K; optimally doped with T c=91 K; overdoped with T c=84, 81, 70, and 58 K; as well asmore » optimally doped Bi 2Sr 2Ca 2Cu 3O 10+x with T c=110 K. Our first observation is that, as the temperature drops through T c, the loss function in the range up to 2 eV displays a change of temperature dependence as compared to the temperature dependence in the normal state. This effect at—or close to—T c depends strongly on doping, with a sign change for weak overdoping. The size of the observed change in Coulomb energy, using an extrapolation with reasonable assumptions about its q dependence, is about the same size as the condensation energy that has been measured in these compounds. Our results therefore lend support to the notion that the Coulomb energy is an important factor for stabilizing the superconducting phase. Lastly, because of the restriction to small momentum, our observations do not exclude a possible significant contribution to the condensation energy of the Coulomb energy associated with the region of q around (π,π).« less
  • The optical conductivity of CuO{sub 2} (copper-oxygen) planes in p- and n-type cuprates thin films at various doping levels is deduced from highly accurate reflectivity data. The temperature dependence of the real part {sigma} {sub 1} ({omega}) of this optical conductivity and the corresponding spectral weight allow to track the opening of a partial gap in the normal state of n-type Pr{sub 2-x}Ce {sub x}CuO{sub 4} (PCCO) but not of p-type Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (BSCCO) cuprates. This is a clear difference between these two families of cuprates, which we briefly discuss. In BSCCO, the change of the electronicmore » kinetic energy E {sub kin}-deduced from the spectral weight-at the superconducting transition is found to cross over from a conventional BCS behavior (increase of E {sub kin} below T {sub c}) to an unconventional behavior (decrease of E {sub kin} below T {sub c}) as the free carrier density decreases. This behavior appears to be linked to the energy scale over which spectral weight is lost and goes into the superfluid condensate, hence may be related to Mott physics.« less
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