Quasiparticle undressing in a dynamic Hubbard model: exact diagonalization study

Abstract

Dynamic Hubbard models have been proposed as extensions of the conventional Hubbard model to describe the orbital relaxation that occurs upon double occupancy of an atomic orbital. These models give rise to pairing of holes and superconductivity in certain parameter ranges. Here we explore the changes in carrier effective mass and quasiparticle weight and in one- and two-particle spectral functions that occur in a dynamic Hubbard model upon pairing, by exact diagonalization of small systems. It is found that pairing is associated with lowering of effective mass and increase of quasiparticle weight, manifested in transfer of spectral weight from high to low frequencies in one- and two-particle spectral functions. This 'undressing' phenomenology resembles observations in transport, photoemission and optical experiments in high T_c cuprates. This behavior is contrasted with that of a conventional electron-hole symmetric Holstein-like model with attractive on-site interaction, where pairing is associated with 'dressing' instead of 'undressing'.

References in corpus (6)

• On the Doping and Temperature Dependence of the Mass Enhancement Observed in the Cuprate Bi2212
• Mobility of the Doped Holes and the Antiferromagnetic Correlations in Underdoped High-T_c Cuprates
• Dynamic Hubbard Model
• Why holes are not like electrons: A microscopic analysis of the differences between holes and electrons in condensed matter
• Quasiparticle Liquid in the Highly Overdoped Bi2212
• Quantum Monte Carlo and exact diagonalization study of a dynamic Hubbard model

Cited by in corpus (19)

• Anisotropic superconductivity in the two-dimensional electron-phonon system
• The toy model for the high-Tc superconductivity
• Electronic dynamic Hubbard model: exact diagonalization study
• Why holes are not like electrons. II. The role of the electron-ion interaction
• Kinetic energy driven superconductivity, the origin of the Meissner effect, and the reductionist frontier
• Spin currents in superconductors
• Ultrafast Mott transition driven by nonlinear electron-phonon interaction
• Effective doublon and hole temperatures in the photo-doped dynamic Hubbard model
• Charge expulsion, charge inhomogeneity and phase separation in dynamic Hubbard models
• Dynamic Hubbard model: kinetic energy driven charge expulsion, charge inhomogeneity, hole superconductivity, and Meissner effect
• Why holes are not like electrons. III. How holes in the normal state turn into electrons in the superconducting state
• Dynamic Hubbard Model: Effect of Finite Boson Frequency
• The Spectral Decomposition of the Helium atom two-electron configuration in terms of Hydrogenic orbitals
• Two-site dynamical mean field theory for the dynamic Hubbard model
• Quantum Monte Carlo Study of a Dynamic Hubbard Model
• How Alfven's theorem explains the Meissner effect
• Optical conductivity for a dimer in the Dynamic Hubbard model
• Dynamic Hubbard model for solids with hydrogen-like atoms
• Pair production and ionizing radiation from superconductors