Raman scattering from superconducting gap excitations in the presence of a magnetic field

Journal Article · Wed Apr 01 04:00:00 EST 1981 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.23.3213· OSTI ID:6449643

Sooryakumar, R; Klein, M V

We recently observed, using Raman scattering as a probe, the superconducting gap excitation in 2H-NbSe/sub 2/. This was seen by the appearance of two new Raman-active modes of different symmetry A (18 cm/sup -1/) and E (15 cm/sup -1/) when the sample is superconducting. In this paper we present further experimental details and results that confirm the theory of Balseiro and Falicov, which shows that the new modes borrow their Raman activity from low-lying charge-density-wave (CDW) phonons. Evidence of this direct coupling between superconducting electrons and the CDW phonon is seen by the behavior of the modes in a magnetic field. Such behavior of the Raman spectra is explained in terms of a model involving a complex gap. The effect of lifetime broadening of the CDW phonon and consequences of varying the coupling strength are presented.

• Research Organization: Department of Physics and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801
• OSTI ID: 6449643
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 23:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY GAP
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERMIONS
HYDROGEN
LEPTONS
MAGNETIC FIELDS
NIOBIUM COMPOUNDS
NIOBIUM SELENIDES
NONMETALS
PHONONS
PHYSICAL PROPERTIES
PLASMA WAVES
QUASI PARTICLES
RAMAN EFFECT
SELENIDES
SELENIUM COMPOUNDS
SUPERCONDUCTIVITY
TRACE AMOUNTS
TRANSITION ELEMENT COMPOUNDS