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Title: New developments in the theory of HTSC

Abstract

The superconductor is supposed to consist of alternating layers of two kinds: (1) layers with an attractive electron interaction and an effective mass of usual magnitude, (2) layers without interaction and with a large effective mass. The overlap between the layers is assumed to be small, its energy, t, being much less than {Delta}. It is shown, that such a model explains the most peculiar property found in experiments on electronic Raman light scattering in BSCCO 2212: different threshold values for the Raman satellite measured at two different polarizations of the incident and scattered light. The tunneling conductance G(V) = dJ/dV is analyzed for the same model. In order to fit the qualitative features of experimental data, it is assumed that the tunneling probability to the normal layers is much less, than to the superconducting layers. The conductance is calculated for the case t {much_lt} {Delta}. A brief analysis is given for the case t {approximately} {Delta}, which proves that such an assumption definitely contradicts the experimental data for BSCCO. The possible nature of the electronic states in the normal layers is discussed. In connection with the experimental discovery (angle resolved photoemission spectroscopy, ARPES) of the extended saddle point singularitiesmore » in the electron spectrum of a variety of HTSC consequences are derived for T{sub c} and {Delta} in a simple model. A large enhancement of superconductivity is possible if the singularity has a sufficient extension and is located close to the Fermi energy. In order to explain the anisotropy of the energy gap, observed in ARPES experiments, on the basis of the {open_quotes}extended saddle point singularities{close_quotes} an assumption is done that the Coulomb interactions are weakly screened, i.e. the Debye screening radius is much larger than the lattice period; this makes the electron interaction long ranged (E-L model).« less

Authors:
Publication Date:
Research Org.:
Argonne National Lab., IL (United States)
Sponsoring Org.:
USDOE Office of Energy Research, Washington, DC (United States)
OSTI Identifier:
456355
Report Number(s):
ANL/MSD/PP-84430
ON: DE97002723; TRN: 97:011968
DOE Contract Number:  
W-31109-ENG-38
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Sep 1994
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS; 66 PHYSICS; BISMUTH OXIDES; SUPERCONDUCTIVITY; STRONTIUM OXIDES; CALCIUM OXIDES; COPPER OXIDES; YTTRIUM OXIDES; BARIUM OXIDES; HIGH-TC SUPERCONDUCTORS; LAYERS; ANISOTROPY; ENERGY GAP; FERMI LEVEL; PHOTOEMISSION; MATHEMATICAL MODELS

Citation Formats

Abrikosov, A.A. New developments in the theory of HTSC. United States: N. p., 1994. Web. doi:10.2172/456355.
Abrikosov, A.A. New developments in the theory of HTSC. United States. doi:10.2172/456355.
Abrikosov, A.A. Thu . "New developments in the theory of HTSC". United States. doi:10.2172/456355. https://www.osti.gov/servlets/purl/456355.
@article{osti_456355,
title = {New developments in the theory of HTSC},
author = {Abrikosov, A.A.},
abstractNote = {The superconductor is supposed to consist of alternating layers of two kinds: (1) layers with an attractive electron interaction and an effective mass of usual magnitude, (2) layers without interaction and with a large effective mass. The overlap between the layers is assumed to be small, its energy, t, being much less than {Delta}. It is shown, that such a model explains the most peculiar property found in experiments on electronic Raman light scattering in BSCCO 2212: different threshold values for the Raman satellite measured at two different polarizations of the incident and scattered light. The tunneling conductance G(V) = dJ/dV is analyzed for the same model. In order to fit the qualitative features of experimental data, it is assumed that the tunneling probability to the normal layers is much less, than to the superconducting layers. The conductance is calculated for the case t {much_lt} {Delta}. A brief analysis is given for the case t {approximately} {Delta}, which proves that such an assumption definitely contradicts the experimental data for BSCCO. The possible nature of the electronic states in the normal layers is discussed. In connection with the experimental discovery (angle resolved photoemission spectroscopy, ARPES) of the extended saddle point singularities in the electron spectrum of a variety of HTSC consequences are derived for T{sub c} and {Delta} in a simple model. A large enhancement of superconductivity is possible if the singularity has a sufficient extension and is located close to the Fermi energy. In order to explain the anisotropy of the energy gap, observed in ARPES experiments, on the basis of the {open_quotes}extended saddle point singularities{close_quotes} an assumption is done that the Coulomb interactions are weakly screened, i.e. the Debye screening radius is much larger than the lattice period; this makes the electron interaction long ranged (E-L model).},
doi = {10.2172/456355},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Sep 01 00:00:00 EDT 1994},
month = {Thu Sep 01 00:00:00 EDT 1994}
}

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