MOTT TRANSITION IN AN EXACTLY SOLVABLE K.S.S.H. MODEL

1991 ◽  
Vol 05 (06n07) ◽  
pp. 985-998 ◽  
Author(s):  
Arianna Montorsi ◽  
Mario Rasetti
Keyword(s):  
Phase Space ◽  
Order Parameter ◽  
Finite Size ◽  
Mott Transition ◽  
Temperature Phase ◽  
Zero Temperature ◽  
Coupling Constant ◽  
Gutzwiller Approximation ◽  
Exactly Solvable ◽  
Half Filling

The solution of the K.S.S.H.-like model shown to be exactly solvable in any number of dimensions, for a particular choice of the coupling constant describing the hopping process amplitude, both for finite size and in the thermodynamic limit, is discussed in detail. The analysis of the zero-temperature phase space in d = 2 shows that the model exhibits a transition in the number of doubly occupied sites order parameter, which at half-filling coincides with the Mott transition found for the Hubbard model in the Gutzwiller approximation.

THE DIMER-CLUSTER FERMI-LINEARIZED HUBBARD MODEL: GROUND STATE AND PHASE SPACE

1990 ◽  
Vol 04 (09) ◽  
pp. 613-623 ◽  
Author(s):  
A. MONTORSI ◽  
M. RASETTI
Keyword(s):  
Phase Space ◽  
Hubbard Model ◽  
Ground State ◽  
Order Parameter ◽  
Temperature Phase ◽  
Zero Temperature ◽  
Supercoherent State

The zero temperature phase space for the Hubbard model is constructed — in the frame of fermionic linearization with a two-site (dimer) cluster — resorting to its ground state, realized in the form of supercoherent state for the model dynamical superalgebra. Such phase space is characterized by the existence of regions in which the pairing order parameter is different from zero.

scholarly journals SUPERFLUID, STAGGERED STATE, AND MOTT INSULATOR OF REPULSIVELY INTERACTING THREE-COMPONENT FERMIONIC ATOMS IN OPTICAL LATTICES

2013 ◽  
Vol 27 (12) ◽  
pp. 1330008 ◽  
Author(s):  
KENSUKE INABA ◽  
SEI-ICHIRO SUGA
Keyword(s):  
Phase Transitions ◽  
Low Temperatures ◽  
Optical Lattices ◽  
Quantum Phase Transitions ◽  
Mott Transition ◽  
Temperature Phase ◽  
Superfluid State ◽  
Fermionic Atoms ◽  
Site Characteristic ◽  
Half Filling

We review our theoretical analysis of repulsively interacting three-component fermionic atoms in optical lattices. We discuss quantum phase transitions at around half filling with a balanced population by focusing on Mott transitions, staggered ordering, and superfluidity. At half filling (with 3/2 atoms per site), characteristic Mott transitions are induced by the anisotropic interactions, where two-particle repulsions between any two of the three colors have different strengths. At half filling, two types of staggered ordered states appear at low temperatures depending on the anisotropy of the interactions. As the temperature increases, phase transitions occur from the staggered ordered states to the unordered Mott states. Deviating from half filling, an exotic superfluid state appears close to a regime in which the Mott transition occurs. We explain the origin of these phase transitions and present the finite-temperature phase diagrams.

AN IMPROVED ONE-LOOP ANALYSIS OF THE λϕ4 THEORY AT FINITE TEMPERATURE

1987 ◽  
Vol 02 (03) ◽  
pp. 713-728 ◽  
Author(s):  
SWEE-PING CHIA
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Zero Temperature ◽  
Coupling Constant ◽  
Loop Analysis ◽  
Temperature Dependent ◽  
Effective Coupling ◽  
Loop Approximation ◽  
The One ◽  
Dependent Mass

The λϕ4 theory with tachyonic mass is analyzed at T ≠ 0 using an improved one-loop approximation in which each of the bare propagators in the one-loop diagram is replaced by a dressed propagator to take into account the higher loop effects. The dressed propagator is characterized by a temperature-dependent mass which is determined by a self-consistent relation. Renomalization is found to be necessarily temperature-dependent. Real effective potential is obtained, giving rise to real effective mass and real coupling constant. For T < Tc, this is achieved by first shifting the ϕ field by its zero-temperature vacuum expectation value. The effective coupling constant is found to exhibit the striking behavior that it approaches a constant nonzero value as T → ∞.

scholarly journals Effects of disorder on the non-zero temperature Mott transition

2005 ◽  
Vol 71 (20) ◽  
Author(s):  
M. C. O. Aguiar ◽  
V. Dobrosavljević ◽  
E. Abrahams ◽  
G. Kotliar
Keyword(s):  
Mott Transition ◽  
Zero Temperature ◽  
Effects Of Disorder

scholarly journals Macroscopic degeneracy and order in the 3D plaquette Ising model

2015 ◽  
Vol 29 (20) ◽  
pp. 1550109 ◽  
Author(s):  
Desmond A. Johnston ◽  
Marco Mueller ◽  
Wolfhard Janke
Keyword(s):  
Low Temperature ◽  
Magnetic Order ◽  
Finite Size ◽  
Temperature Phase ◽  
Finite Size Scaling ◽  
First Order ◽  
Magnetic Order Parameter ◽  
First Order Transition ◽  
Definition Of ◽  
Low Temperature Phase

The purely plaquette 3D Ising Hamiltonian with the spins living at the vertices of a cubic lattice displays several interesting features. The symmetries of the model lead to a macroscopic degeneracy of the low-temperature phase and prevent the definition of a standard magnetic order parameter. Consideration of the strongly anisotropic limit of the model suggests that a layered, “fuki-nuke” order still exists and we confirm this with multi-canonical simulations. The macroscopic degeneracy of the low-temperature phase also changes the finite-size scaling corrections at the first-order transition in the model and we see this must be taken into account when analyzing our measurements.

Parameterization of the coupling between strain and order parameter for LuF[SeO3]

2014 ◽  
Vol 47 (2) ◽  
pp. 701-711 ◽  
Author(s):  
Oxana V. Magdysyuk ◽  
Melanie Müller ◽  
Robert E. Dinnebier ◽  
Christian Lipp ◽  
Thomas Schleid
Keyword(s):  
Phase Transition ◽  
Order Parameter ◽  
Structural Phase ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Time Resolved ◽  
Synchrotron Powder Diffraction ◽  
First Order Phase Transition ◽  
Temperature Phase Transition ◽  
First Order Phase

The high-temperature phase transition of LuF[SeO3] has been characterized by time-resolved high-resolution synchrotron powder diffraction. On heating, a second-order structural phase transition was found at 393 K, while on cooling the same phase transition occurs at 371 K, showing a large hysteresis typical for a first-order phase transition. Detailed analysis using sequential and parametric whole powder pattern fitting revealed that the coupling between the strain and the displacive order parameter determines the behaviour of the material during the phase transition. Different possible coupling mechanisms have been evaluated and the most probable rationalized.

scholarly journals Rise and fall of Landau’s quasiparticles while approaching the Mott transition

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andrej Pustogow ◽  
Yohei Saito ◽  
Anja Löhle ◽  
Miriam Sanz Alonso ◽  
Atsushi Kawamoto ◽  
...  
Keyword(s):  
Fermi Liquid ◽  
Mott Transition ◽  
Dynamical Localization ◽  
Strong Increase ◽  
Unconventional Superconductors ◽  
Scattering Rate ◽  
Complex Interactions ◽  
Liquid Behavior ◽  
Half Filling ◽  
Correlation Strength

AbstractLandau suggested that the low-temperature properties of metals can be understood in terms of long-lived quasiparticles with all complex interactions included in Fermi-liquid parameters, such as the effective mass m⋆. Despite its wide applicability, electronic transport in bad or strange metals and unconventional superconductors is controversially discussed towards a possible collapse of the quasiparticle concept. Here we explore the electrodynamic response of correlated metals at half filling for varying correlation strength upon approaching a Mott insulator. We reveal persistent Fermi-liquid behavior with pronounced quadratic dependences of the optical scattering rate on temperature and frequency, along with a puzzling elastic contribution to relaxation. The strong increase of the resistivity beyond the Ioffe–Regel–Mott limit is accompanied by a ‘displaced Drude peak’ in the optical conductivity. Our results, supported by a theoretical model for the optical response, demonstrate the emergence of a bad metal from resilient quasiparticles that are subject to dynamical localization and dissolve near the Mott transition.

scholarly journals The pion quasiparticle in the low-temperature phase of QCD

2018 ◽  
Vol 175 ◽  
pp. 07045
Author(s):  
Bastian B. Brandt ◽  
Anthony Francis ◽  
Harvey B. Meyer ◽  
Daniel Robaina ◽  
Kai Zapp
Keyword(s):  
Low Temperature ◽  
Finite Temperature ◽  
Quark Mass ◽  
Pion Mass ◽  
Effective Theory ◽  
Temperature Phase ◽  
Zero Temperature ◽  
Low Temperature Phase

We extend our previous studies [PhysRevD.90.054509, PhysRevD.92.094510] of the pion quasiparticle in the low-temperature phase of two-flavor QCD with support from chiral effective theory. This includes the analysis performed on a finite temperature ensemble of size 20 × 643 at T ≈ 151MeV and a lighter zero-temperature pion mass mπ ≈ 185 MeV. Furthermore, we investigate the Gell-Mann–Oakes-Renner relation at finite temperature and the Dey-Eletsky-Ioffe mixing theorem at finite quark mass.

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