Extended Falicov-Kimball model: Hartree-Fock vs DMFT approach

• URL: http://arxiv.org/abs/2011.07493v1
• Date: Sun, 15 Nov 2020 10:43:55 GMT
• Title: Extended Falicov-Kimball model: Hartree-Fock vs DMFT approach
• Authors: Konrad Jerzy Kapcia (Institute of Nuclear Physics, Polish Academy of Sciences), Romuald Lema\'nski (Institute of Low Temperature and Structure Research, Polish Academy of Sciences), Marcin Jakub Zygmunt (Institute of Mathematics, University of Silesia)
• Abstract summary: We study the extended Falicov-Kimball model at half-filling within the Hartree-Fock approach (HFA) We show that the HFA description of the ground state properties of the model is equivalent to the exact DMFT solution.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: In this work, we study the extended Falicov-Kimball model at half-filling within the Hartree-Fock approach (HFA) (for various crystal lattices) and compare the results obtained with the rigorous ones derived within the dynamical mean field theory (DMFT). The model describes a system, where electrons with spin-$\downarrow$ are itinerant (with hopping amplitude $t$), whereas those with spin-$\uparrow$ are localized. The particles interact via on-site $U$ and intersite $V$ density-density Coulomb interactions. We show that the HFA description of the ground state properties of the model is equivalent to the exact DMFT solution and provides a qualitatively correct picture also for a range of small temperatures. It does capture the discontinuous transition between ordered phases at $U=2V$ for small temperatures as well as correct features of the continuous order-disorder transition. However, the HFA predicts that the discontinuous boundary ends at the isolated-critical point (of the liquid-gas type) and it does not merge with the continuous boundary. This approach cannot also describe properly a change of order of the continuous transition for large $V$ as well as various metal-insulator transitions found within the DMFT.

Related papers

• Ancilla quantum measurements on interacting chains: Sensitivity of entanglement dynamics to the type and concentration of detectors [46.76612530830571]
  We consider a quantum many-body lattice system that is coupled to ancillary degrees of freedom (detectors'') We explore the dynamics of density and of entanglement entropy in the chain, for various values of $rho_a$ and $M$.
  arXiv  Detail & Related papers  (2023-11-21T21:41:11Z)
• Kondo frustration via charge fluctuations: a route to Mott localisation [0.0]
  We propose a minimal effective impurity model that captures the phenomenology of the Mott-Hubbard metal-insulator transition (MIT) This involves extending the standard Anderson impurity model Hamiltonian to include an explicit coupling $J$. For the case of attractive local bath correlations ($U_b0$), the extended Anderson impurity model sheds new light on several aspects of the DMFT phase diagram.
  arXiv  Detail & Related papers  (2023-02-05T07:48:25Z)
• Coupled Fredkin and Motzkin chains from quantum six- and nineteen-vertex models [4.965221313169878]
  We generalize the area-law violating models of Fredkin and Motzkin spin chains into two dimensions. The Hamiltonian is frustration free, and its projectors generate ergodic dynamics within the subspace of height configuration that are non negative.
  arXiv  Detail & Related papers  (2022-10-06T16:46:05Z)
• Exact solution for the filling-induced thermalization transition in a 1D fracton system [0.0]
  We study a random circuit model of constrained fracton dynamics in which particles undergo random local motion. We identify an exact solution for the critical density $n_c$. We show that there is a universal value of the correlation length exponent $nu = 2$ near the transition.
  arXiv  Detail & Related papers  (2022-10-05T18:00:02Z)
• Spin Current Density Functional Theory of the Quantum Spin-Hall Phase [59.50307752165016]
  We apply the spin current density functional theory to the quantum spin-Hall phase. We show that the explicit account of spin currents in the electron-electron potential of the SCDFT is key to the appearance of a Dirac cone.
  arXiv  Detail & Related papers  (2022-08-29T20:46:26Z)
• A first-principles calculation of electron-phonon interactions for the $\text{C}_2\text{C}_\text{N}$ and $\text{V}_\text{N}\text{N}_\text{B}$ defects in hexagonal boron nitride [52.77024349608834]
  Quantum emitters in two-dimensional hexagonal boron nitride (h-BN) have generated significant interest. Recent observations of Fourier transform (FT) limited photons emitted from h-BN flakes at room temperature.
  arXiv  Detail & Related papers  (2022-07-28T23:31:38Z)
• Full counting statistics of interacting lattice gases after an expansion: The role of the condensate depletion in the many-body coherence [55.41644538483948]
  We study the full counting statistics (FCS) of quantum gases in samples of thousands of interacting bosons. FCS reveals the many-body coherence from which we characterize iconic states of interacting lattice bosons.
  arXiv  Detail & Related papers  (2022-07-28T13:21:57Z)
• Engineering the Radiative Dynamics of Thermalized Excitons with Metal Interfaces [58.720142291102135]
  We analyze the emission properties of excitons in TMDCs near planar metal interfaces. We find suppression or enhancement of emission relative to the point dipole case by several orders of magnitude. nanoscale optical cavities are a viable pathway to generating long-lifetime exciton states in TMDCs.
  arXiv  Detail & Related papers  (2021-10-11T19:40:24Z)
• Phase transition of Frustrated Ising model via D-wave Quantum Annealing Machine [0.0]
  We study the frustrated Ising model on the two-dimensional $L times L$ square lattice with ferromagnetic (FM) nearest-neighbor and antiferromagnetic diagonal-neighbor interactions. We find the FM to stripe order phase transition, through observations of the magnetization $M$, energy, magnetic susceptibility and structure factor.
  arXiv  Detail & Related papers  (2021-10-11T10:02:33Z)
• Stability of the Fulde-Ferrell-Larkin-Ovchinnikov states in anisotropic systems and critical behavior at thermal $m$-axial Lifshitz points [0.0]
  We argue that for isotropic, continuum systems the phase diagram hosting a long-range-ordered FFLO-type phase cannot be stable to fluctuations at any temperature. We point out the possibility of a robust, fine-tuning free occurrence of a quantum Lifshitz point in the phase diagram of imbalanced Fermi mixtures.
  arXiv  Detail & Related papers  (2021-09-01T21:56:28Z)
• Anisotropy-mediated reentrant localization [62.997667081978825]
  We consider a 2d dipolar system, $d=2$, with the generalized dipole-dipole interaction $sim r-a$, and the power $a$ controlled experimentally in trapped-ion or Rydberg-atom systems. We show that the spatially homogeneous tilt $beta$ of the dipoles giving rise to the anisotropic dipole exchange leads to the non-trivial reentrant localization beyond the locator expansion.
  arXiv  Detail & Related papers  (2020-01-31T19:00:01Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.