Novel attractive pairing interaction in strongly correlated superconductors release_ejcsvkoeavfvxigwf66bw35vti

by Priyo Adhikary, Tanmoy Das

Published in SciPost Physics by Stichting SciPost.

2019  

Abstract

Conventional and unconventional superconductivity, respectively, arise from attractive (electron-phonon) and repulsive (many-body Coulomb) interactions with fixed-sign and sign-reversal pairing symmetries. Although heavy-fermions, cuprates, and pnictides are widely believed to be unconventional superconductors, recent evidence in one of the heavy fermion superconductor (CeCu<jats:inline-formula><jats:alternatives><jats:tex-math>_2</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi /><mml:mn>2</mml:mn></mml:msub></mml:math></jats:alternatives></jats:inline-formula>Si<jats:inline-formula><jats:alternatives><jats:tex-math>_2</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi /><mml:mn>2</mml:mn></mml:msub></mml:math></jats:alternatives></jats:inline-formula>) indicate the presence of a novel conventional type pairing symmetry beyond the electron-phonon coupling. We present a new mechanism of attractive potential between electrons, mediated by emergent boson fields (vacuum or holon) in the strongly correlated mixed valence compounds. In the strong coupling limit, localized electron sites are protected from double occupancy, which results in an emergent holon fields. The holon states can, however, attract conduction electrons through valence fluctuation channel, and the resulting doubly occupied states with local and conduction electrons condenseas Cooper pairs with onsite, fixed-sign, s-wave pairing symmetry. We develop the corresponding self-consistent theory of superconductivity, and compare the results with experiments. Our theory provides a new mechanism of superconductivity whose applicability extends to the wider class of intermetallic/mixed-valence materials and other flat-band metals.
In application/xml+jats format

Archived Files and Locations

application/pdf  692.5 kB
file_3ji7vxfycfhdxk5stcdjjvpq6a
scipost.org (web)
web.archive.org (webarchive)
Read Archived PDF
Preserved and Accessible
Type  article-journal
Stage   published
Date   2019-12-09
Container Metadata
Open Access Publication
In DOAJ
In Keepers Registry
ISSN-L:  2542-4653
Work Entity
access all versions, variants, and formats of this works (eg, pre-prints)
Catalog Record
Revision: b547fea8-c939-4ef0-be61-305c7a9691f4
API URL: JSON