Singularities of a superconductor order parameter due to an electronic topological phase transition

Journal Article · Tue Jun 01 04:00:00 EDT 1982 · Sov. J. Low Temp. Phys. (Engl. Transl.); (United States)

OSTI ID:6417466

Makarov, V I

It is shown that if the difference between the Fermi energy epsilon-c/sub F/ and the critical energy epsilon-c/sub K/ at which an electronic topological transition occurs takes a value in the energy range 0< or = epsilon-c/sub F/-epsilon-c/sub K/ or =w/sub r/ under the effect of elastic lattice deformations, then two kinds of root singularities occur in the dependence of the superconductor order parameter ..delta..(p,..omega..) on the momentum p and the frequency ..omega.. is the characteristic frequency of the order of the boundary frequency of the phonon spectrum). The first kind of singularity in ..delta..(p,..omega..) is related to the fact that according to the Eliashberg equation, a layer of isoenergetic surfaces epsilon-c(p) = epsilon-c/sub F/ +- ..omega..' takes part in the formation of the function ..delta..(p,..omega..). The quantity ..omega..' varies over the range from zero to ..omega../sub r/. If the surface epsilon-c(p) = epsilon-c/sub K/ is in this layer, then for a virtual change in the Fermi energy epsilon-c/sub F/ +- ..omega..' at the frequency ..omega..' = Vertical Bar epsilon-c/sub F/-epsilon-c/sub K/ Vertical Bar an electronic topological transition occurs. The singularity in ..delta..(p,..omega..) indeed corresponds to this ''virtual'' topological transition, which exerts no influence on the properties of metals in the normal state.

• Research Organization: Physicotechnical Institute, Academy of Sciences, Ukrainian SSR, Khar'kov
• OSTI ID: 6417466
• Journal Information: Sov. J. Low Temp. Phys. (Engl. Transl.); (United States), Journal Name: Sov. J. Low Temp. Phys. (Engl. Transl.); (United States) Vol. 8:6; ISSN SJLPD
• Country of Publication: United States
• Language: English

Related Subjects

656102* -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
&amp; Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DEFORMATION
ELASTICITY
ENERGY
ENERGY LEVELS
FERMI LEVEL
GORKOV-ELIASHBERG THEORY
MECHANICAL PROPERTIES
ORDER PARAMETERS
PHASE TRANSFORMATIONS
STRESSES
SUPERCONDUCTORS
TENSILE PROPERTIES