arXiv:1808.02925 · Physical review. B./Physical review. B
Thermal and quantum lattice fluctuations in Peierls chains
Manuel Weber, Fakher F. Assaad, Martin Hohenadler
Abstract
Thermodynamic and spectral properties of electrons coupled to quantum phonons are studied in the framework of the one-dimensional spinless Holstein model. Using quantum Monte Carlo simulations and an efficient exact estimator for the specific heat based on the properties of the perturbation expansion we calculate the specific heat and compressibility for the entire range of electron-phonon couplings and phonon frequencies. Our results reveal how the Peierls gap and long-range order at zero temperature as well as the significant renormalization of electrons and phonons---revealed by the corresponding spectral functions---manifest themselves in the specific heat. We also quantitatively assess the validity for the widely used classical phonon approximation and identify the electronic contribution predicted for a Tomonaga-Luttinger liquid.