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Dynamical two electron states in a Hubbard-Davydov model

L. Cruzeiro-Hansson·J. C. Eilbeck·J. L. Marin·F. M. Russell
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Abstract

We study a model in which a Hubbard Hamiltonian is coupled to the dispersive phonons in a classical nonlinear lattice. Our calculations are restricted to the case where we have only two quasi-particles of opposite spins, and we investigate the dynamics when the second quasi-particle is added to a state corresponding to a minimal energy single quasi-particle state. Depending on the parameter values, we find a number of interesting regimes. In many of these, discrete breathers (DBs) play a prominent role with a localized lattice mode coupled to the quasiparticles. Simulations with a purely harmonic lattice show much weaker localization effects. Our results support the possibility that DBs are important in HTSC.

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L. Cruzeiro-Hansson, J. C. Eilbeck, J. L. Marin, F. M. Russell. 2004-04-30. Dynamical two electron states in a Hubbard-Davydov model. https://arxiv.org/abs/cond-mat/0404743

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