On the broadening of low dimension van Hove singularities in oxide superconductors
نویسنده
چکیده
2014 It is pointed out that the transverse couplings and, accessorily, the longitudinal scattering by doping and phonons broaden enough the 2d van Hove singularities of Cu O2 planes to prevent their spontaneous Jahn Teller splitting. The tetragonal-orthorhombic phase changes observed in La2-x Srx Cu O4-y and Y Ba2 Cu3 O7-03B4 have then different origins and nature. In good crystals, this broadening is not sufficient to destroy the antiferromagnetic or superconductive instabilities, contrary to the scattering by vacancies along the 1d Cu O chains in underst0153chiometric Y Ba2 Cu3 O7-03B4. A previous analysis of superconductivity, starting from quasilowdimensionality and weak coupling, is revised to take this broadening into account. J. Phys. France 49 (1988) 1435-1441 AOÚT 1988, Classification Physics Abstracts 71.00 74.00
منابع مشابه
Van Hove scenario for high Tc superconductors
We give a general description of our approach which explains many physical properties in the superconducting and normal states of almost 2D high Tc superconductors (HTSC). This 2D character leads to the existence of Van Hove singularities or saddle points in the band structure of these compounds. 2007 Elsevier B.V. All rights reserved.
متن کاملSpin orthogonality catastrophe in two-dimensional antiferromagnets and superconductors.
We compute the spectral function of a spin S hole injected into a two-dimensional antiferromagnet or superconductor in the vicinity of a magnetic quantum critical point. We show that, near Van Hove singularities, the problem maps onto that of a static vacancy carrying excess spin S. The hole creation operator is characterized by a new boundary anomalous dimension and a vanishing quasiparticle r...
متن کاملVan Hove Singularity and Superconductivity in Disordered Hubbard Model
We apply the Coherent Potential Approximation (CPA) to a simple extended Hubbard model with a nearest and next nearest neighbour hopping for disordered superconductors with s–, d– and p–wave pairing. We show how the Van Hove singularities in the electron density of states enhance the transition temperature Tc for exotic superconductors in a clean and weakly disordered system. The Anderson theor...
متن کاملMicroscopic theory of the coupling of intrinsic Josephson oscillations and phonons
A microscopic theory for the coupling of intrinsic Josephson oscillations and dispersive phonon branches in layered superconductors is developed. Thereby the effect of phonons on the electronic c-axis transport enters through an effective longitudinal dielectric function. This coupling provides an explanation of recently observed subgap resonances in the Idc-Vdc-curve of anisotropic cuprate sup...
متن کاملar X iv : c on d - m at / 9 40 70 77 v 2 2 2 Ju l 1 99 4 Antiferromagnetic and van Hove Scenarios for the Cuprates : Taking the Best
A theory for the high temperature superconductors is proposed. Holes are spin-1/2, charge e, quasiparticles strongly dressed by spin fluctuations. Based on their dispersion, it is claimed that the experimentally observed van Hove singularities of the cuprates are likely originated by antiferromagnetic (AF) correlations. From the two carriers problem in the 2D t-J model, an effective Hamiltonian...
متن کامل