Dilute Fermi Liquid of Heavy Polarons in Copper Oxide Superconductors
In this paper we point out that a large body of data on the newly discovered copper oxide superconductors points to the existence in these materials of a new type of dilute fermi liquid composed of heavy polarons, which we believe acquire their mass magnetically. Each polaron is a hole doped into the host material, a Mott insulator, self-trapped in a well, much the way a hole added to an alkali halide is trapped. The polaron is mobile, has a mass m* of approximately 6 electron masses, and has ail ionization energy, an upper limit on its binding energy, of approximately 0.15 eV. The fermi energy of the polaron liquid in La2-xSrxCuO4 with x = 0.15 is roughly 80 meV. The smallness of this energy is unprecedented in the phenomenology of superconductivity and is probably the key to understanding these materials.
KeywordsOscillator Strength Optical Conductivity Fermi Liquid Hall Coefficient Mott Insulator
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