Excitations of the one-dimensional, two-band Peierls-Hubbard model at three-quarters filling in the large-Ulimit
Jia Ming Shi, Robijn Bruinsma, A. R. Bishop
We investigate the ground state and the excitation spectrum associated with the localized defect states of the three-quarter-filled, one-dimensional Peierls-Hubbard model. In the continuum limit with an infinite, on-site electron-electron repulsion energy U, the Hamiltonian is mapped onto the N=1 Gross-Neveu model, in which irrationally charged soliton-antisoliton pairs are formed upon doping, while polarons are unstable. Corrections due to finite-U effects are discussed. However, discreteness effects are found to support excitations absent from the continuum field theory. In particular, for large band separation a novel type of polaron can be formed with a highly localized electronic wave function surrounded by an extended pattern of local lattice distortion.
Physical review. B, Condensed matter•Apr 15, 1993•2 citations