Matches in SemOpenAlex for { <https://semopenalex.org/work/W2056646885> ?p ?o ?g. }
Showing items 1 to 54 of
54
with 100 items per page.
- W2056646885 endingPage "680" @default.
- W2056646885 startingPage "679" @default.
- W2056646885 abstract "The modern theory of conventional superconductivity is based upon the concept of quantum states with broken gauge symmetry providing non-zero values for the so-called anomalous averages , . Being applied to the simplest Gorikov-like semiphenomenological electronic scenario for a metal superconductor, this idea (in the mean field approximation) leads towards a complete description of all properties of ordinary superconductors as a manifestation of macroscopic quantum phase coherence. Currently there exists already strong experimental evidence that the newly discovered high Tc superconductors exhibit the same quantum coherence effects including the highly characteristic quantity for these phenomena, namely the doubled electronic charge. On these grounds one can expect that the high Tc superconductors should also be described by anomalous averages of the same kind. The only question is whether Gorikov's scenario is still sufficient or we need a new scenario instead in order to grasp the whole situation. In the case of Gorikov's scenario one needs to explain how the strong electron-electron coupling (no matter of what origin) can be consistent with the system stability condition. Yet there is another argument in favour of a new scenario. The large variety of the new SC properties cannot be explained by a model with too limited number of physical parameters. In our dealing with the problem of a possible new scenario we have suggested that in order to understand the high Tc superconductors one should not perhaps go so far as to doubt the one-particle approximation and to introduce the Hubbard-like models, RVB and so on. Taking into account the crystalline structure of perfect high Tc superconductors we have assumed within the one-particle description the two overlapping bands approach which was proposed by Suhl, Mattias and Walker (USA) and Moskalenko (USSR) as early as in 1959. To obtain qualitatively new results we have suggested a sharp asymmetry between the two bands (one being practically a local energy level close to the Fermi level) and also a special structure of direct electron-electron interaction with dominating interband scattering of singlet electron pairs described by an amplitude g. As the final analysis has shown, an inevitable but comparatively small splitting of the two bands does not invalidate the results of the model. As to the peculiar structure of interaction we believe it might be explained through a strong electron-optical phonon coupling due to the Jahn-Teller-like instability manifested in tetragonal-orthorhombic transitions of HTc samples. The model just outlined can indeed yield high Tc. In the mean field approximation (with two superconductivity order parameters) the order of magnitude of Tc is given by Tc ~ (|g|N(o)/2)2 EF where N(o) is the density of states in the wide band at the Fermi level and EF is a wide band width. There is an exponentially sharp decline of Tc while overdoping or underdoping the system and there is also a broad plateau when the narrow band is filled partially (the heavy fermion situation). The other results of calculations including thermodynamics and also kinetic properties for the normal state do not contradict experiments except for the linear temperature dependence of the specific heat observed sometimes. But one must take into account that in reality all high Tc superconductors are in fact disordered solutions, and it is necessary to consider the dirty alloy limit with Anderson's theorem being violated because of the narrow band existence. At the same time, as analysis shows, the mean field approximation is not good enough for the model (the small parameter is only (log 2/|g|N(o))-1) and therefore one has to apply Green's functions technique in order to correct the results. There is also a possibility that the magnetic properties connected with localized spins (if there are any) must be taken into account as well." @default.
- W2056646885 created "2016-06-24" @default.
- W2056646885 creator A5000237540 @default.
- W2056646885 date "1988-10-01" @default.
- W2056646885 modified "2023-09-27" @default.
- W2056646885 title "A TWO-BAND SUPERCONDUCTOR WITH A NARROW BAND NEAR THE FERMI LEVEL" @default.
- W2056646885 doi "https://doi.org/10.1142/s0217979288000500" @default.
- W2056646885 hasPublicationYear "1988" @default.
- W2056646885 type Work @default.
- W2056646885 sameAs 2056646885 @default.
- W2056646885 citedByCount "0" @default.
- W2056646885 crossrefType "journal-article" @default.
- W2056646885 hasAuthorship W2056646885A5000237540 @default.
- W2056646885 hasConcept C121332964 @default.
- W2056646885 hasConcept C147120987 @default.
- W2056646885 hasConcept C177909632 @default.
- W2056646885 hasConcept C181966813 @default.
- W2056646885 hasConcept C186769553 @default.
- W2056646885 hasConcept C26873012 @default.
- W2056646885 hasConcept C33444154 @default.
- W2056646885 hasConcept C40636707 @default.
- W2056646885 hasConcept C54101563 @default.
- W2056646885 hasConcept C62520636 @default.
- W2056646885 hasConceptScore W2056646885C121332964 @default.
- W2056646885 hasConceptScore W2056646885C147120987 @default.
- W2056646885 hasConceptScore W2056646885C177909632 @default.
- W2056646885 hasConceptScore W2056646885C181966813 @default.
- W2056646885 hasConceptScore W2056646885C186769553 @default.
- W2056646885 hasConceptScore W2056646885C26873012 @default.
- W2056646885 hasConceptScore W2056646885C33444154 @default.
- W2056646885 hasConceptScore W2056646885C40636707 @default.
- W2056646885 hasConceptScore W2056646885C54101563 @default.
- W2056646885 hasConceptScore W2056646885C62520636 @default.
- W2056646885 hasIssue "05" @default.
- W2056646885 hasLocation W20566468851 @default.
- W2056646885 hasOpenAccess W2056646885 @default.
- W2056646885 hasPrimaryLocation W20566468851 @default.
- W2056646885 hasRelatedWork W1005167852 @default.
- W2056646885 hasRelatedWork W1505724036 @default.
- W2056646885 hasRelatedWork W2001722264 @default.
- W2056646885 hasRelatedWork W2004919150 @default.
- W2056646885 hasRelatedWork W2029409377 @default.
- W2056646885 hasRelatedWork W2037986828 @default.
- W2056646885 hasRelatedWork W2072023418 @default.
- W2056646885 hasRelatedWork W2082621931 @default.
- W2056646885 hasRelatedWork W2125818263 @default.
- W2056646885 hasRelatedWork W4299315939 @default.
- W2056646885 hasVolume "02" @default.
- W2056646885 isParatext "false" @default.
- W2056646885 isRetracted "false" @default.
- W2056646885 magId "2056646885" @default.
- W2056646885 workType "article" @default.