Renormalization of the electron-phonon interaction: a reformulation of the BCS-gap equation

Hübsch, A.; Becker, K. W.

doi:10.1140/epjb/e2003-00180-9

Cited by 14 publications

(3 citation statements)

References 8 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Meanwhile the method of flow equations has been applied to many systems. Apart from those already mentioned we list the following applications: Anderson impurity model [25,27,95] Fano-Anderson and Anderson lattice [83], spin-boson models and dissipation [26,28,31,40,44,66,76,77,78,92], qbit and spin-boson model [97], electronphonon interaction and superconductivity [32,34,49,52,88,115], superconductivity and impurities [39], boson fermion model [50,71,93,103], Tomonaga-Luttinger model [79,94], one-dimensional fermions [85], Kondo model [36,70,84,87,108,112,118,120], Fermi and Luttinger liquid [35,73], sine-Gordon model [56,69], QED [29,30,43], QCD and general [24,51,…”

Section: Other Applicationsmentioning

confidence: 99%

Flow equations and normal ordering: a survey

Wegner¹

2006

J. Phys. A: Math. Gen.

View full text Add to dashboard Cite

Abstract. First we give an introduction to the method of diagonalizing or blockdiagonalizing continuously a Hamiltonian and explain how this procedure can be used to analyze the two-dimensional Hubbard model. Then we give a short survey on applications of this flow equation on other models. Finally we outline, how symmetry breaking can be introduced by means of a symmetry breaking of the normal ordering, not of the Hamiltonian.

show abstract

Section: Other Applicationsmentioning

confidence: 99%

Flow equations and normal ordering: a survey

Wegner¹

2006

J. Phys. A: Math. Gen.

View full text Add to dashboard Cite

show abstract

“…28,29 The PRM was introduced 15 as an alternative approach to many-particle systems and was already applied to a number of different systems. Examples are the investigation of phonon-mediated superconductivity starting from an explicit expression for the electron-phonon interaction 30 and the discussion of the metal-insulator transition in the Holstein model. 31 Many-particle systems in the presence of strong correlations such as the PAM were also investigated.…”

Section: Projector-based Renormalization Methodsmentioning

confidence: 99%

“…The desired expectation values can then be determined from the free energy by functional derivatives. 30,32 The second way employs an additional unitary transformation for the operator variable A, for which the expectation value is evaluated,…”

Section: Projector-based Renormalization Methodsmentioning

confidence: 99%

Extended periodic Anderson model close to a valence transition: A projector-based renormalization approach

2010

View full text Add to dashboard Cite

The one-dimensional periodic Anderson model with an additional Coulomb repulsion U fc between localized f and conduction electrons has been investigated using the projector-based renormalization method. Due to the presence of U fc and the hybridization V between localized and conduction electrons, various gaps are found in the quasiparticle dispersion k . The number of gaps depends on the density of the localized electrons. Moreover, a valence transition from an integer to a mixed f valence is found as a function of the bare f level energy f . Its dependence on various model parameters is investigated for fixed total electron density. In particular, the transition is sharpened either by increasing U fc or by decreasing the hybridization or the temperature.

show abstract

Coexistence of spin‐singlet s‐ and d‐wave and spin‐triplet p‐wave order parameters in anisotropic superconductors

Gonczarek

Krzyzosiak²,

Jacak

et al. 2007

Physica Status Solidi (b)

View full text Add to dashboard Cite

A two-dimensional model of an anisotropic superconductor with a relatively wide partially filled conduction band and a dispersion relation implying singularities in the density of states is considered. Employing the conformal transformation method and choosing the Fourier harmonics as the complete and orthogonal basis for 4v C irreducible representations the symmetry of the superconducting order parameter is identified. Detailed numerical calculations are carried out for the two-dimensional tight-binding band model and compared with the results obtained within the BCS-type approximation. Diagrams of stable superconducting states in the coordinates V coincide, whereas the tight-binding results and some obtained within the BCS-type approximation are dissimilar. The influence of the attractive or repulsive onsite interaction on the stability of the s-wave order parameter is explained. The developed and widely illustrated formalism can be easily applied to some more composed models.

show abstract

Renormalization of the electron-phonon interaction: a reformulation of the BCS-gap equation

Cited by 14 publications

References 8 publications

Flow equations and normal ordering: a survey

Flow equations and normal ordering: a survey

Extended periodic Anderson model close to a valence transition: A projector-based renormalization approach

Coexistence of spin‐singlet s‐ and d‐wave and spin‐triplet p‐wave order parameters in anisotropic superconductors

Contact Info

Product

Resources

About