Quantum Monte Carlo study of the one-dimensional Holstein model of spinless fermions

Article

关键词: ELECTRON-PHONON SYSTEMS;    SCHRIEFFER-HEEGER MODEL;    SUBGAP OPTICAL-ABSORPTION;    LATTICE FLUCTUATIONS;    CONFORMAL-INVARIANCE;    TRANS-POLYACETYLENE;    HEISENBERG CHAIN;    PHASE-DIAGRAM;    GROUND-STATE;    CHARGE;   

DOI  :  10.1103/PhysRevB.53.9676

来源: SCIE

【 摘 要 】

The Holstein model of spinless fermions interacting with dispersionless phonons in one dimension is studied by a Green's function Monte Carlo technique. The ground-state energy, first fermionic excited state, density wave correlations, and mean lattice displacements are calculated for lattices of up to 16 sites, for one fermion per two sites, i.e., a half-filled band. Results are obtained for values of the fermion hopping parameter of t=0.1 omega, omega, and 10 omega, where omega is the phonon frequency. At a finite fermion-phonon coupling g there is a transition from a metallic phase to an insulating phase in which there is charge-density-wave order. Finite-size scaling is found to hold in the metallic phase and is used to extract the coupling dependence of the Luttinger liquid parameters, u(rho), and K-rho, the velocity of charge excitations, and the correlation exponent respectively. For free fermions (g=0) and for strong coupling (g(2) much greater than t omega) our results agree well with known analytic results.

【 授权许可】

Free