engleski

Thermodynamics of strongly correlated electrons in a three-band model

Strongly correlated electrons in copper oxide planes are modelled by a random tiling of CuO$_4$ molecules at finite temperatures. This model is a non-perturbative extension of Gutzwiller's variational assumption. An effective one-particle theory is constructed through the use of a combinatorial transform to express the problem in momentum space, without averaging over occupation numbers in real space. Temporal correlations are lost, because of the Gutzwiller approximation, implemented by taking one kind of spins to be static. Thermodynamic functions can be computed at any temperature and filling. A Mott-Hubbard transition is found in doping, but cannot be crossed in temperature. The effective Fermi liquid can be strongly renormalized, though it does not break down. In the derivation of the model, a formal connection between projected hopping and pair confinement is established.

strong correlations; Mott-Hubbard transition; annealed disorder; confinement

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