Preprints of the Keldysh Institute of Applied Mathematics
RUS  ENG    JOURNALS   PEOPLE   ORGANISATIONS   CONFERENCES   SEMINARS   VIDEO LIBRARY   PACKAGE AMSBIB  
General information
Latest issue
Archive

Search papers
Search references

RSS
Latest issue
Current issues
Archive issues
What is RSS



Keldysh Institute preprints:
Year:
Volume:
Issue:
Page:
Find






Personal entry:
Login:
Password:
Save password
Enter
Forgotten password?
Register


Preprints of the Keldysh Institute of Applied Mathematics, 2020, 009, 75 pp.
DOI: https://doi.org/10.20948/prepr-2020-9
(Mi ipmp2800)
 

Translational-invariant bipolarons and superconductivity

V. D. Lakhno
References:
Abstract: A translation-invariant bipolaron theory of superconductivity based, like Bardeen–Cooper–Schrieffer theory, on Fröhlich Hamiltonian is presented. Here the role of Cooper pairs belongs to TI bipolarons which are pairs of spatially delocalized electrons whose correlation length of a coupled state is small. The presence of Fermi surface leads to stabilization of such states in its vicinity and a possibility of their Bose–Einstein condensation (BEC).
The theory provides a natural explanation of the existence of a pseudogap phase preceding the superconductivity and enables one to estimate the temperature of a transition $T^*$ from a normal state to a pseudogap one.
It is shown that the temperature of BEC of TI bipolarons determines the temperature of a superconducting transition $T_c$ which depends not on the bipolaron effective mass but on the ordinary mass of a band electron. This removes restrictions on the upper limit of $T_c$ for a strong electron-phonon interaction. A natural explanation is provided for the angular dependence of the superconducting gap which is determined by the angular dependence of the phonon spectrum.
It is demonstrated that a lot of experiments on thermodynamic and transport characteristics, Josephson tunneling and angle-resolved photoemission spectroscopy (ARPES) of high-temperature superconductors does not contradict the concept of a TI bipolaron mechanism of superconductivity in these materials. Possible ways of enhancing $T_c$ and producing new room-temperature superconductors are discussed on the basis of the theory suggested.
Keywords: squeezed vacuum, pairing, nonideal bose-gas, crossover, correlation length, magnetic field, cuprates, kinks, transformation Bogolyubov.
Document Type: Preprint
Language: Russian
Citation: V. D. Lakhno, “Translational-invariant bipolarons and superconductivity”, Keldysh Institute preprints, 2020, 009, 75 pp.
Citation in format AMSBIB
\Bibitem{Lak20}
\by V.~D.~Lakhno
\paper Translational-invariant bipolarons and superconductivity
\jour Keldysh Institute preprints
\yr 2020
\papernumber 009
\totalpages 75
\mathnet{http://mi.mathnet.ru/ipmp2800}
\crossref{https://doi.org/10.20948/prepr-2020-9}
Linking options:
  • https://www.mathnet.ru/eng/ipmp2800
  • https://www.mathnet.ru/eng/ipmp/y2020/p9
  • Citing articles in Google Scholar: Russian citations, English citations
    Related articles in Google Scholar: Russian articles, English articles
    Препринты Института прикладной математики им. М. В. Келдыша РАН
    Statistics & downloads:
    Abstract page:365
    Full-text PDF :116
    References:36
     
      Contact us:
     Terms of Use  Registration to the website  Logotypes © Steklov Mathematical Institute RAS, 2024