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Related papers: The HMF model for fermions and bosons

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Many-particle systems pose commonly known computational challenges in quantum theory. The obstacles arise from the difficulty in finding sets of eigenvalues and eigenvectors of the underlying Hamiltonian while enforcing fermion or boson…

Quantum Physics · Physics 2025-02-07 Josep Batle , Boris A. Malomed

We study a one-dimensional lattice model of fractional statistics in which particles have next-nearest-neighbor hopping between sites which depends on the occupation number at the intermediate site and a statistical parameter $\phi$. The…

Strongly Correlated Electrons · Physics 2021-06-30 Sreemayee Aditya , Diptiman Sen

In the stochastic mean-field (SMF) approach, an ensemble of initial values for a selected set of one-body observables is formed by stochastic sampling from a phase-space distribution that reproduces the initial quantum fluctuations.…

Nuclear Theory · Physics 2015-06-22 Bulent Yilmaz , Denis Lacroix , Resul Curebal

We discuss the dynamics and thermodynamics of the Brownian Mean Field (BMF) model which is a system of N Brownian particles moving on a circle and interacting via a cosine potential. It can be viewed as the canonical version of the…

Statistical Mechanics · Physics 2015-06-16 Pierre-Henri Chavanis

We present for the first time to the nuclear physics community the Hamiltonian Mean Field (HMF) model. The model can be solved analytically in the canonical ensemble and shows a second-order phase transition in the thermodynamic limit.…

Nuclear Theory · Physics 2009-11-06 V. Latora , A. Rapisarda

In this work, improvements are introduced to the current models of the ideal Fermi gas and the ideal Bose gas by incorporating the quantum nature of phase space, which is directly linked to the uncertainty principle. These improved models…

We discuss some basic aspects of the dynamics of a homogenous Fermi gas in a weak random potential, under negligence of the particle pair interactions. We derive the kinetic scaling limit for the momentum distribution function with a…

Mathematical Physics · Physics 2009-11-13 Thomas Chen , Itaru Sasaki

In this work, we describe the dynamics of a Bose-Einstein condensate interacting with a degenerate Fermi gas, at zero temperature. First, we analyze the mean-field approximation of the many-body Schr\"odinger dynamics and prove emergence of…

Mathematical Physics · Physics 2025-07-04 Esteban Cárdenas , Joseph K. Miller , Nataša Pavlović

The phenomenon of the so called Fermion condensation, a phase transition analogous to Bose condensation but for Fermions, postulated in the past to occur in systems with strong momentum dependent forces, is reanalysed in a model with…

Condensed Matter · Physics 2009-10-28 J. Dukelsky , V. A. Khodel , P. Schuck , V. R. Shaginyan

We introduce a new method for deriving the time-dependent Hartree or Hartree-Fock equations as an effective mean-field dynamics from the microscopic Schroedinger equation for fermionic many-particle systems in quantum mechanics. The method…

Mathematical Physics · Physics 2016-11-29 Sören Petrat , Peter Pickl

From sand piles to electrons in metals, one of the greatest challenges in modern physics is to understand the behavior of an ensemble of strongly interacting particles. A class of quantum many-body systems such as neutron matter and cold…

Quantum Gases · Physics 2010-06-01 Sylvain Nascimbène , Nir Navon , Kaijun Jiang , Frédéric Chevy , Christophe Salomon

The effect of nearest-neighbor coupling on the thermodynamic and dynamical properties of the ferromagnetic Hamiltonian Mean Field model (HMF) is studied. For a range of antiferromagnetic nearest-neighbor coupling, a canonical first order…

Statistical Mechanics · Physics 2009-11-11 Alessandro Campa , Andrea Giansanti , David Mukamel , Stefano Ruffo

The nearest-neighbor quantum-antiferromagnetic (AF) Heisenberg model for spin 1/2 on a two-dimensional square lattice is studied in the auxiliary-fermion representation. Expressing spin operators by canonical fermionic particles requires a…

Strongly Correlated Electrons · Physics 2009-11-10 Jan Brinckmann , Peter Woelfle

We consider a dilute homogeneous mixture of bosons and spin-polarized fermions at zero temperature. We first construct the formal scheme for carrying out systematic perturbation theory in terms of single particle Green's functions. We…

Condensed Matter · Physics 2009-11-07 Alexander P. Albus , Simon A. Gardiner , Fabrizio Illuminati , Martin Wilkens

The fermionic Hubbard model (FHM)[1], despite its simple form, captures essential features of strongly correlated electron physics. Ultracold fermions in optical lattices[2, 3] provide a clean and well-controlled platform for simulating…

We present a theoretical framework and a calculational scheme to study the coexistence and competition of thermodynamic phases in quantum statistical mechanics. The crux of the method is the realization that the microscopic Hamiltonian,…

Strongly Correlated Electrons · Physics 2009-11-07 G. Ortiz , C. D. Batista

A generic feature of systems with long-range interactions is the presence of {\it quasi-stationary} states with non-Gaussian single particle velocity distributions. For the case of the Hamiltonian Mean Field (HMF) model, we demonstrate that…

Systems with long-range interactions can reach a Quasi Stationary State (QSS) as a result of a violent collisionless relaxation. If the system mixes well (ergodicity), the QSS can be predicted by the statistical theory of Lynden-Bell (1967)…

Statistical Mechanics · Physics 2009-11-11 P. H. Chavanis

We present a new theoretical approach for the study of the phase diagram of interacting quantum particles: bosons, fermions or spins. In the neighborhood of a phase transition, the expected renormalization group structure is recovered both…

Strongly Correlated Electrons · Physics 2009-10-31 Pietro Gianinetti , Alberto Parola

A model of hybridized bosons and fermions is studied beyond the mean field approximation. The divergent boson self-energy at zero temperature makes the Cooper pairing of fermions impossible.The frequency and momentum dependence of the self-…

Condensed Matter · Physics 2009-10-28 A. S. Alexandrov