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arXiv · 2105.12576

Bond-Peierls polaron: Moderate mass enhancement and current-carrying ground state

Matthew R. Carbone·Andrew J. Millis·David R. Reichman·John Sous
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Abstract

We study polarons in the one-dimensional Bond-Peierls electron-phonon model, in which phonons on bonds of a lattice modulate the hopping of electrons between lattice sites, and contrast the results to those known for the Breathing-Mode Peierls problem. By inspecting the atomic limit, we show that polaronic dressing and mass enhancement of Bond-Peierls polarons depend on the momentum dependence of the phonons. For dispersionless phonons, Bond-Peierls polarons are perfectly localized in the atomic limit, unlike their Breathing-mode counterparts, because the carrier creates a string of phonon excitations that can only be annihilated via processes that retrace the carrier to its original site. However, inclusion of phonon dispersion leads to a non-divergent polaron mass even in the atomic limit and depending on the form of the phonon dispersion may lead to a transition to a non-zero-momentum ground state akin to that found in the Breathing-mode Peierls model.

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Matthew R. Carbone, Andrew J. Millis, David R. Reichman, John Sous. 2021-05-26. Bond-Peierls polaron: Moderate mass enhancement and current-carrying ground state. https://doi.org/10.1103/physrevb.104.l140307

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