Excitation spectra and spin gap of the half-filled Holstein-Hubbard model

Abstract

Single-- and two-particle excitation spectra of the one-dimensional, half-filled Holstein-Hubbard model are calculated using the continuous-time quantum Monte Carlo method. In the metallic phase, the results are consistent with a Luther-Emery liquid that has gapped spin and single-particle excitations but a gapless charge mode. However, given the initially exponential dependence of the spin gap on the backscattering matrix element, the numerical excitation spectra appear gapless in the weak-coupling regime, and therefore resemble those of a Luttinger liquid. The Mott phase has the expected charge gap and gapless spin excitations. The Peierls state shows a charge, spin and single-particle gap, a soft phonon mode, backfolded shadow bands and soliton excitations. Arguments and numerical evidence for the existence of a nonzero spin gap throughout the metallic phase are provided in terms of equal-time spin and charge correlation functions.

10 pages, 8 figures, 1 table, published version

References in corpus (19)

• Continuous-time Monte Carlo methods for quantum impurity models
• Efficient DMFT-simulation of the Holstein-Hubbard Model
• Diagrammatic Determinantal methods: projective schemes and applications to the Hubbard-Holstein model
• First- and Second Order Phase Transitions in the Holstein-Hubbard 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
• Competition between antiferromagnetic and charge order in the Hubbard-Holstein model
• Photoemission spectra of many-polaron systems
• 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
• Temperature- and quantum phonon effects on Holstein-Hubbard bipolarons
• Dynamic charge correlations near the Peierls transition
• Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons
• Peierls to superfluid crossover in the one-dimensional, quarter-filled Holstein model
• Carrier-density effects in many-polaron systems

Cited by in corpus (19)

• Phonon-Mediated Long-Range Attractive Interaction in One-Dimensional Cuprates
• Diagrammatic Monte Carlo method for many-polaron problems
• Superconductivity, charge-density waves, antiferromagnetism, and phase separation in the Hubbard-Holstein model
• Excitation spectra and correlation functions of quantum Su-Schrieffer-Heeger models
• A coupled cluster framework for electrons and phonons
• Nature of ground states in one-dimensional electron-phonon Hubbard models at half-filling
• Time-dependent variational principle with controlled bond expansion for matrix product states
• Phonon spectral function of the one-dimensional Holstein-Hubbard model
• Interplay of Site and Bond Electron-Phonon Coupling in One Dimension
• Interplay of charge, spin and lattice degrees of freedom on the spectral properties of the one-dimensional Hubbard-Holstein model
• Continuous-time quantum Monte Carlo for fermion-boson lattice models: Improved bosonic estimators and application to the Holstein model
• Variational wave functions for the spin-Peierls transition in the Su-Schrieffer-Heeger model with quantum phonons
• Equivalence of Rashba-Hubbard and Hubbard chains
• Competing Correlated Insulators in multi-orbital systems coupled to phonons
• Chebyshev pseudosite matrix product state approach for the spectral functions of electron-phonon coupling systems
• Steady-state Peierls transition in nanotube quantum simulator
• Intertwined fluctuations and isotope effects in the Hubbard-Holstein model on the square lattice from functional renormalization
• The one-dimensional Holstein model revisited
• Phase diagram of the two-dimensional Hubbard-Holstein model: enhancement of $s$-wave pairing between charge and magnetic orders