Peierls to superfluid crossover in the one-dimensional, quarter-filled Holstein model
arXiv:1206.2864 · doi:10.1088/0953-8984/25/1/014005
Abstract
We use continuous-time quantum Monte Carlo simulations to study retardation effects in the metallic, quarter-filled Holstein model in one dimension. Based on results which include the one- and two-particle spectral functions as well as the optical conductivity, we conclude that with increasing phonon frequency the ground state evolves from one with dominant diagonal order---2k_F charge correlations---to one with dominant off-diagonal fluctuations, namely s-wave pairing correlations. In the parameter range of this crossover, our numerical results support the existence of a spin gap for all phonon frequencies. The crossover can hence be interpreted in terms of preformed pairs corresponding to bipolarons, which are essentially localised in the Peierls phase, and "condense" with increasing phonon frequency to generate dominant pairing correlations.
11 pages, 5 figures
References in corpus (13)
- Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
- Continuous-time Monte Carlo methods for quantum impurity models
- Diagrammatic Determinantal methods: projective schemes and applications to the Hubbard-Holstein model
- Metallicity in the half-filled Holstein-Hubbard model
- Phase diagram for the one-dimensional Hubbard-Holstein model: A density-matrix renormalization group study
- Phase diagram of the one dimensional Hubbard-Holstein Model at 1/2 and 1/4 filling
- Quantum lattice dynamical effects on the single-particle excitations in 1D Mott and Peierls insulators
- Retardation effects in the Holstein-Hubbard chain at half-filling
- Adiabatic-antiadiabatic crossover in a spin-Peierls chain
- Effect of Electron-Phonon Interaction Range for a Half-Filled Band in One Dimension
- The quantum vs classical aspects of one dimensional electron-phonon systems revisited by the renormalization group method
- Dynamic charge correlations near the Peierls transition
- Dominant particle-hole contributions to the phonon dynamics in the spinless one-dimensional Holstein model