Observation of electron pairing by coherent Raman scattering in the high Tc superconductors

Y. Biton, R. Shuker

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Taking advantage of the fact that Raman scattering is a correlation function of the single particle density of states we have employed it to measure the correlation obtained as the electrons from the Cooper pairs. Indeed, the idea is quite simple in principle: Raman scattering reveals the extent or lack of correlations of the scattering excitations. As the electrons undergo pairing at the critical superconducting temperature they correlate and thus scatter coherently. If the correlation length is of the order of a wavelength the scattering adds coherently resulting in a corresponding sudden increase in the Raman scattering intensity at the transition temperature. We have observed this experimentally by measuring the Raman intensity of the electronic quasi particle excitation continuum. The electronic Raman spectrum spans the region up to a few thousand cm-1. The intensity of the peak of this quadratic continuum as well as the integrated intensity exhibit sharp increase at the critical temperature, exhibiting the formation of the Cooper pairs and the resulting correlation. The Raman intensity continues to increase with decreasing temperature which indicates the continuous increase in the number of Cooper pairs. This is an elegant manifestation of the pairing process and is unique in its simplicity. In particular for the fresh and good sample the transition temperature can be accurately determined to within fraction of a degree. The sample deteriorates under extended exposure to laser light.

Original languageEnglish
Title of host publicationProceedings of the International Quantum Electronics Conference (IQEC'94)
PublisherPubl by IEEE
ISBN (Print)0780319737
StatePublished - 1 Dec 1994
EventProceedings of the 21st International Quantum Electronics Conference (IQEC'94) - Anaheim, CA, USA
Duration: 8 May 199413 May 1994

Publication series

NameProceedings of the International Quantum Electronics Conference (IQEC'94)

Conference

ConferenceProceedings of the 21st International Quantum Electronics Conference (IQEC'94)
CityAnaheim, CA, USA
Period8/05/9413/05/94

ASJC Scopus subject areas

  • Engineering (all)

Fingerprint

Dive into the research topics of 'Observation of electron pairing by coherent Raman scattering in the high Tc superconductors'. Together they form a unique fingerprint.

Cite this