Dynamical two
electron states in a Hubbard-Davydov model
L. Cruzeiro-Hansson,
J.C. Eilbeck, J.L. Marin and F.M. Russell
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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