Projected Wavefunctions and High Temperature Superconductivity
Abstract
We study the Hubbard model with parameters relevant to the cuprates, using variational Monte Carlo with projected d-wave states. For doping 0 < x < 0.35 we obtain a superconductor whose order parameter tracks the observed nonmonotonic Tc(x). The variational parameter Delta_{var}(x) scales with the (pi,0) ``hump'' and T* seen in photoemission. Projection leads to incoherence in the spectral function, and from the singular behavior of its moments we obtain the nodal quasiparticle weight Z which vanishes linearly in x, though the Fermi velocity remains finite as x approaches zero. The Drude weight D_{low} and superfluid density are consistent with experiments, and D_{low} scales with Z.
Cite
@article{arxiv.cond-mat/0101121,
title = {Projected Wavefunctions and High Temperature Superconductivity},
author = {Arun Paramekanti and Mohit Randeria and Nandini Trivedi},
journal= {arXiv preprint arXiv:cond-mat/0101121},
year = {2009}
}
Comments
4 pages, 5 EPS figures. (1) Many improvements including discussion of n(k) and superfluid density. (2) Added comparison with slave boson mean field theory. (3) Added new references