Observation of Leggett's Collective Mode in a MultibandMgB2Superconductor

G. Blumberg, A. Mialitsin, B. S. Dennis, M. V. Klein, N. D. Zhigadlo, J. Karpinski
2007 Physical Review Letters  
We report observation of Leggett's collective mode in a multi-band MgB2 superconductor with T_c=39K arising from the fluctuations in the relative phase between two superconducting condensates. The novel mode is observed by Raman spectroscopy at 9.4 meV in the fully symmetric scattering channel. The observed mode frequency is consistent with theoretical considerations based on the first principle computations.
doi:10.1103/physrevlett.99.227002 pmid:18233316 fatcat:4iqvaenp2zfkxgdx4dgq5nnso4