Repulsive vs. attractive Hubbard model: transport properties and spin-lattice relaxation rate

Abstract

We contrast the transport properties (dc resistivity, Seebeck coefficient), optical conductivity, spectral functions, dynamical magnetic susceptibility, and the NMR $1/T_1$ spin-lattice relaxation rate of the repulsive and attractive infinite-dimensional Hubbard models in the paramagnetic phase for a generic band filling. The calculations are performed in a wide temperature interval using the dynamical mean-field theory with the numerical renormalization group as the impurity solver. The attractive case exhibits significantly more complex temperature dependences which can be explained by the behavior of the half-filled Hubbard model in external magnetic field with constant magnetization, to which the attractive Hubbard model maps through the partial particle-hole transformation. The resistivity is non-monotonous for strongly attractive case: it peaks significantly above the MIR value at a temperature $T_{\max }$ where the quasiparticle band disappears. For both signs of $U$ we find particle-hole asymmetry in the self-energy at low energies, but with the opposite kind of excitations having longer lifetime. This leads to a strong suppression of the slope of the Seebeck coefficient in the attractive case, rather than an enhancement as in the repulsive case. The spin-lattice relaxation rate in the strongly attractive case has a non-monotonic temperature dependence, thereby revealing the pairing fluctuations.

19 pages, 20 figures. Final version

References in corpus (19)

• Many-Body Physics with Ultracold Gases
• The numerical renormalization group method for quantum impurity systems
• Real-time dynamics in Quantum Impurity Systems: A Time-dependent Numerical Renormalization Group Approach
• Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
• A thermoelectric heat engine with ultracold atoms
• Energy resolution and discretization artefacts in the numerical renormalization group
• A Numerical Renormalization Group approach to Green's Functions for Quantum Impurity Models
• How bad metals turn good: spectroscopic signatures of resilient quasiparticles
• Non-Drude universal scaling laws for the optical response of local Fermi liquids
• Dynamical mean-field theory and numerical renormalization group study of superconductivity in the attractive Hubbard model
• Competition between antiferromagnetic and charge order in the Hubbard-Holstein model
• Cold Attractive Spin Polarized Fermi Lattice Gases and the Doped Positive U Hubbard Model
• Extremely correlated Fermi liquid theory meets Dynamical mean-field theory: Analytical insights into the doping-driven Mott transition
• Field dependent quasiparticles in the infinite dimensional Hubbard model
• Convergence acceleration and stabilization for dynamical-mean-field-theory calculations
• Transport functions for hypercubic and Bethe lattices
• Quasiparticle properties of strongly correlated electron systems with itinerant metamagnetic behavior
• Isotope effects in the Hubbard-Holstein model within dynamical mean-field theory
• Condensed Matter Physics With Light And Atoms: Strongly Correlated Cold Fermions in Optical Lattices

Cited by in corpus (10)

• Exciton Mott transition revisited
• Quantum critical local spin dynamics near the Mott metal-insulator transition in infinite dimensions
• Site-Specific Spin Reorientation in Antiferromagnetic State of Quantum System SeCuO${}_3$
• Evolution of the density of states at the Fermi level across the metal-to-insulator crossover in alkali doped zeolite
• Spin Seebeck coefficient and spin-thermal diffusion in the two-dimensional Hubbard model
• The perils of minimal coupling to electromagnetic field in quantum many-body systems
• Collective excitations in competing phases in two and three dimensions
• Natural orbital impurity solver for real-frequency properties at finite temperature
• Universal Mott quantum criticality in a modified periodic Anderson model
• Probing the pseudogap and beyond: Examining single-particle properties of the hole- and electron-doped Hubbard model