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Relaxation study of elementary excitations in Bi2212 investigated by picosecond Raman spectroscopy
Author(s) -
Machtoub L. H.,
Suemoto T.,
Shimoyama J.,
Kishio K.
Publication year - 2002
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.861
Subject(s) - picosecond , raman spectroscopy , magnon , relaxation (psychology) , condensed matter physics , spectroscopy , phonon , population , raman scattering , physics , symmetry (geometry) , chemistry , quantum mechanics , laser , mathematics , psychology , social psychology , demography , geometry , ferromagnetism , sociology
Abstract We report a relaxation study of elementary excitations in heavily underdoped Bi 2 Sr 2 CaCu 2 O 8+δ (Bi2212) using picosecond Raman Spectroscopy. In B 1 g symmetry, the two‐magnon peak shows a super‐linear power dependence which is ascribed to excess magnon population. In contrast, the broad feature observed in A 1 g + B 2 g symmetry shows a sub‐linear power dependence, suggesting a different origin from the two‐magnon scattering. We could recognize a time response <0.5 ps for the B 1 g two‐magnon peak. We also observed super‐linear behavior in the power dependence of the 295 and 465 cm −1 anti‐Stokes vibrational modes, in contrast to linear behavior on the Stokes side. We propose to explain the non‐linear behavior in terms of non‐equilibrium phonons. Copyright © 2002 John Wiley & Sons, Ltd.