TY - CPAPER
KW - Superconducting films
KW - Photons
KW - Single crystals
KW - High temperature superconductors
KW - Crystal lattices
KW - Laser pulses
KW - Yttrium barium copper oxides
KW - Oxide superconductors
KW - Cooper pair breaking
KW - Ion channeling
KW - Zhang-rice singlet
AU - T Venkatesan
AU - R.P Sharma
AU - Ramamoorthy Ramesh
AU - Y.G Zhao
AU - Insik Jin
AU - S.B Ogale
AU - M Rajeswari
AU - H Zhang
AU - J.R Liu
AU - W.K Chu
AU - Boyed Veal
AU - A Paulikas
AU - H Zheng
AU - C.H Lee
AU - W.L Cao
AU - Bozovic D
AB - Two novel experiments, one concerned with the fast optical response related to Cooper pair breaking using femto-second laser pulses in YBCO films and the second related to uncorrelated dynamic distortions as a function of oxygen concentration for YBCO single crystals by ion channeling, have provided information that may be relevant for understanding the mechanism of superconductivity in high Tc superconductors. In the first case a dramatic resonant photon energy dependence around 1.5 eV in the pair breaking rate has been observed, suggesting that an intermediate excitation may be playing an important role in the depairing process. In the second experiment, ion channeling investigations in YBa2Cu3O7-δ (δ = 0.05 to 0.8) crystals have clearly shown an evolution of the lattice from that of a Debye solid for δ = 0.8 to one exhibiting significant lattice coherence even at much higher temperatures than Tc, with discontinuities which track Tc. These two experimental results are discussed in the light of different mechanisms including the formation of Zhang-Rice singlet or other mechanisms that lead to a non local hole.
BT - Proceedings of the SPIE - The International Society for Optical Engineering
LA - eng
N1 - cited By 0
N2 - Two novel experiments, one concerned with the fast optical response related to Cooper pair breaking using femto-second laser pulses in YBCO films and the second related to uncorrelated dynamic distortions as a function of oxygen concentration for YBCO single crystals by ion channeling, have provided information that may be relevant for understanding the mechanism of superconductivity in high Tc superconductors. In the first case a dramatic resonant photon energy dependence around 1.5 eV in the pair breaking rate has been observed, suggesting that an intermediate excitation may be playing an important role in the depairing process. In the second experiment, ion channeling investigations in YBa2Cu3O7-δ (δ = 0.05 to 0.8) crystals have clearly shown an evolution of the lattice from that of a Debye solid for δ = 0.8 to one exhibiting significant lattice coherence even at much higher temperatures than Tc, with discontinuities which track Tc. These two experimental results are discussed in the light of different mechanisms including the formation of Zhang-Rice singlet or other mechanisms that lead to a non local hole.
PB - SPIE, Bellingham, WA, United States
PY - 1998
SP - 44
EP - 59
T2 - Proceedings of the SPIE - The International Society for Optical Engineering
T3 - SPIE - The International Society for Optical Engineering
TI - Femto-second photoimpedance response and dynamic structural distortions in YBCO samples
VL - 3481
SN - 0277786X
ER -