1998/12/15 by J. Bonča, J. Bonca, S. A. Trugman +2 · 2 citations
Physics and Astronomy · #Condensed matter physics #Electron #Excitation #Excited state #Ground state #Lattice (music) #Phonon #Physics #Physics of Superconductivity and Magnetism #Polaron #Quantum and electron transport phenomena #Quantum electrodynamics #Quantum mechanics #Spectroscopy and Quantum Chemical Studies #Variational method #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.60.1633
24 pages, 11 figures submitted to PRB
arxiv created 1998/12/15 · openalex publication_date 1999/07/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We describe a variational method to solve the Holstein model for an electron coupled to dynamical, quantum phonons on an infinite lattice. The variational space can be systematically expanded to achieve high accuracy with modest computational resources (12-digit accuracy for the one-dimensional polaron energy at intermediate coupling). We compute ground-state and low-lying excited-state properties of the model at continuous values of the wave vector k in essentially all parameter regimes. Our results for the polaron energy band, effective mass, and correlation functions compare favorably with those of other numerical techniques, including the density-matrix renormalization-group technique, the global-local method, and the exact diagonalization technique. We find a phase transition for the first excited state between a bound and unbound system of a polaron and an additional phonon excitation. The phase transition is also treated in strong-coupling perturbation theory.