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Single-particle excitations and phonon softening in the one-dimensional spinless Holstein model

S. Sykora·A. Huebsch·K. W. Becker·G. Wellein·H. Fehske
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Abstract

We investigate the influence of the electron-phonon coupling in the one-dimensional spinless Holstein model at half-filling using both a recently developed projector-based renormalization method (PRM) and an refined exact diagonalization technique in combination with the kernel polynomial method. At finite phonon frequencies the system shows a metal-insulator transition accompanied by the appearance of a Peierls distorted state at a finite critical electron-phonon coupling. We analyze the opening of a gap in terms of the (inverse) photoemission spectral functions which are evaluated in both approaches. Moreover, the PRM approach reveals the softening of a phonon at the Brillouin-zone boundary which can be understood as precursor effect of the gap formation.

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S. Sykora, A. Huebsch, K. W. Becker, G. Wellein, H. Fehske. 2005-01-19. Single-particle excitations and phonon softening in the one-dimensional spinless Holstein model. https://doi.org/10.1103/physrevb.71.045112

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