scholarly journals Pairing symmetry of the one-band Hubbard model in the paramagnetic weak-coupling limit: A numerical RPA study

2015 ◽  
Vol 92 (10) ◽  
Author(s):  
A. T. Rømer ◽  
A. Kreisel ◽  
I. Eremin ◽  
M. A. Malakhov ◽  
T. A. Maier ◽  
...  
Keyword(s):  
Hubbard Model ◽  
Weak Coupling ◽  
Weak Coupling Limit ◽  
Pairing Symmetry ◽  
The One

scholarly journals ON THE WEAK-COUPLING LIMIT FOR BOSONS AND FERMIONS

2005 ◽  
Vol 15 (12) ◽  
pp. 1811-1843 ◽  
Author(s):  
D. BENEDETTO ◽  
M. PULVIRENTI ◽  
F. CASTELLA ◽  
R. ESPOSITO
Keyword(s):  
Boltzmann Equation ◽  
Wigner Function ◽  
Weak Coupling ◽  
Convergence Result ◽  
Weak Coupling Limit ◽  
Perturbative Expansion ◽  
Weak Coupling Regime ◽  
Interacting Particles ◽  
The One ◽  
Bose Einstein

In this paper we consider a large system of bosons or fermions. We start with an initial datum which is compatible with the Bose–Einstein, respectively Fermi–Dirac, statistics. We let the system of interacting particles evolve in a weak-coupling regime. We show that, in the limit, and up to the second order in the potential, the perturbative expansion expressing the value of the one-particle Wigner function at time t, agrees with the analogous expansion for the solution to the Uehling–Uhlenbeck equation. This paper follows the same spirit as the companion work,2 where the authors investigated the weak-coupling limit for particles obeying the Maxwell–Boltzmann statistics: here, they proved a (much stronger) convergence result towards the solution of the Boltzmann equation.

Charge collective modes and dynamic pairing in the three-band Hubbard model. I. Weak-coupling limit

1993 ◽  
Vol 47 (6) ◽  
pp. 3323-3330 ◽  
Author(s):  
Yunkyu Bang ◽  
G. Kotliar ◽  
R. Raimondi ◽  
C. Castellani ◽  
M. Grilli
Keyword(s):  
Hubbard Model ◽  
Weak Coupling ◽  
Weak Coupling Limit ◽  
Collective Modes

One-dimensional Large-U Hubbard Model in Strong Coupling: Charge and Spin Separation

1991 ◽  
Vol 05 (10) ◽  
pp. 1801-1807
Author(s):  
Z. Y. Weng ◽  
D. N. Sheng ◽  
C. S. Ting
Keyword(s):  
Fixed Point ◽  
Hubbard Model ◽  
Weak Coupling ◽  
Composite Particle ◽  
Electron Hole ◽  
Integral Formalism ◽  
One Dimensional ◽  
Coupling Case ◽  
Non Local ◽  
The One

A path-integral formalism of the Hubbard model is used to study the one-dimensional large-U case. It is shown that the bare electron (hole) becomes a composite particle of two decoupled excitations, holon and spinon, together with the non-local string fields. Various correlation functions are analytically derived. The results strongly suggest a U*=∞ fixed point of Hubbard model which is distinct from the weak coupling case.

scholarly journals THE SPECTRAL PROPERTIES OF THE FALICOV–KIMBALL MODEL IN THE WEAK-COUPLING LIMIT

2003 ◽  
Vol 17 (10) ◽  
pp. 2083-2093 ◽  
Author(s):  
PAVOL FARKAŠOVSKÝ
Keyword(s):  
Weak Coupling ◽  
Critical Value ◽  
Exact Diagonalization ◽  
Weak Coupling Limit ◽  
Level Energy ◽  
One Dimensional ◽  
Energy Gaps ◽  
Electron Density Of States ◽  
Insulator Metal Transition ◽  
The One

The f and d electron density of states of the one-dimensional Falicov–Kimball model are studied in the weak-coupling limit by exact diagonalization calculations. The resultant behaviors are used to examine the d electron gap (Δd), the f electron gap (Δf), and the fd electron gap (Δfd) as functions of the f level energy Ef and hybridization V. It is shown that the spinless Falicov–Kimball model behaves fully differently for zero and finite hybridization between f and d states. At zero hybridization the energy gaps do not coincide (Δd ≠ Δf ≠ Δfd), and the activation gap Δfd vanishes discontinuously at some critical value of the f level energy Efc. On the other hand, at finite hybridization all energy gaps coincide and vanish continuously at the insulator-metal transition point Ef = Efc. The importance of these results for a description of real materials is discussed.

Statistical mechanics of quantum one-dimensional damped harmonic oscillators: II

1987 ◽  
Vol 65 (7) ◽  
pp. 715-718 ◽  
Author(s):  
O. N. Borges ◽  
L. A. Amarante Ribeiro
Keyword(s):  
Master Equation ◽  
Weak Coupling ◽  
Weak Coupling Limit ◽  
Harmonic Oscillators ◽  
Equation Approach ◽  
One Dimensional ◽  
Master Equation Approach ◽  
The One ◽  
The Relationship ◽  
Damped Oscillator

We show that the Caldirola–Kanai Hamiltonian of the one-dimensional damped oscillator describes in a specified basis a Gaussian, Markoffian process, in the weak coupling limit. We also discuss which assumption makes the process stationary and clarify the relationship with the master-equation approach.

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