Symmetry of the pairing, isotope effect and mechanism of superconductivity in cuprates

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:64702

Wolf, S A ^[1]; Kresin, V Z ^[2]

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1. Naval Research Lab., Washington, DC (United States)
2. Lawrence Berkeley Lab., CA (United States)

This paper is mainly concerned with the problem of the origin of high {Tc}. S vs d-pairing, the isotope effect, and strong coupling of the carriers to low frequency optical phonon modes are discussed. The main conclusion of the paper can be summarized as follows: (1) The superconducting state in the high {Tc} oxides is characterized by s-wave symmetry. The non-stoichiometric disordered state is gapless with a power law temperature dependence of the NMR relaxation time, heat capacity, penetration depth, etc. The fully oxygenated state of YBCO displays a two gap spectrum with exponential dependence. (2) Non-adiabaticity leads to the peculiar dependence of the carrier concentration (and hence {Tc}) on the isotope substitution. This specific isotope effect manifested in the doped superconductors, is characterized by the minimum value of the isotope coefficient at {Tc} = {Tc}{sub max}. (3) High {Tc} is caused by strong coupling to low frequency optical phonon modes.

• OSTI ID: 64702
• Report Number(s): CONF-940142--; ISBN 0-8194-1453-0
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
COPPER OXIDES
DOPED MATERIALS
ELECTRON-PHONON COUPLING
HIGH-TC SUPERCONDUCTORS
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TRANSITION TEMPERATURE
YTTRIUM OXIDES