BCS and attractive Hubbard model comparative study
نویسندگان
چکیده
منابع مشابه
Evaluation of the BCS Approximation for the Attractive Hubbard Model in One Dimension
The ground state energy and energy gap to the first excited state are calculated for the attractive Hubbard model in one dimension using both the Bethe Ansatz equations and the variational BCS wavefunction. Comparisons are provided as a function of coupling strength and electron density. While the ground state energies are always in very good agreement, the BCS energy gap is sometimes incorrect...
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The low-energy physics of the one-dimensional Pair-Hopping (PH) and attractive Hubbard models are expected to be similar. Based on numerical calculations on small chains, several authors have recently challenged this idea and predicted the existence of a phase transition at half-filling and finite positive coupling for the pair-hopping model. We re-examine the controversy by making systematic c...
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B. Kyung, S. Allen, and A.-M. S. Tremblay Département de Physique and Centre de Recherche sur les Propriétés Électroniques de Matériaux Avancés, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1 Institut Canadien de Recherches Avancées, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1 ~Received 2 October 2000; revised manuscript received 2 March 2001; published 31 July 2001!
متن کاملQUANTUM BREATHERS IN AN ATTRACTIVE FERMIONIC HUBBARD MODEL Quantum breathers in a Hubbard model
In one–dimensional translationally invariant anharmonic lattices, an extended Bloch state with two or more strongly correlated particles is usually called a quantum breather. Here we study an attractive fermionic Hubbard model with two kind of particles of opposite spin. We discuss the existence of breathers, and several effects that break the translational symmetry of the system and localize t...
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ژورنال
عنوان ژورنال: Physical Review B
سال: 2004
ISSN: 1098-0121,1550-235X
DOI: 10.1103/physrevb.70.064511