Effect of electron-phonon interaction range on lattice polaron dynamics: a continuous-time quantum Monte Carlo study
Abstract
We present the numerically exact ground state energy, effective mass, and isotope exponents of a one-dimensional lattice polaron, valid for any range of electron-phonon interaction, applying a new continuous-time Quantum Monte Carlo (QMC) technique in a wide range of coupling strength and adiabatic ratio. The QMC method is free from any systematic finite-size and finite-time-step errors. We compare our numerically exact results with analytical weak-coupling theory and with the strong-coupling expansion. We show that the exact results agree well with the canonical Fr\"ohlich and Holstein-Lang-Firsov theories in the weak and strong coupling limits, respectively, for any range of interaction. We find a strong dependence of the polaron dynamics on the range of interaction. An increased range of interaction has a similar effect to an increased (less adiabatic) phonon frequency: specifically, a reduction in the effective mass.
Keywords
Cite
@article{arxiv.cond-mat/0407250,
title = {Effect of electron-phonon interaction range on lattice polaron dynamics: a continuous-time quantum Monte Carlo study},
author = {P. E. Spencer and J. H. Samson and P. E. Kornilovitch and A. S. Alexandrov},
journal= {arXiv preprint arXiv:cond-mat/0407250},
year = {2009}
}
Comments
27 pages, 16 figures, to appear Phys Rev B. Introduction rewritten, comparison with other authors extended, description of method shortened, improved treatment of weak coupling theory