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Evidence for two distinct energy scales in the Raman spectra of YBa2(CuNi)O6.95

Y. Gallais·A. Sacuto·P. Bourges·Y. Sidis·A. Forget·D. Colson
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Abstract

We report low energy electronic Raman scattering from Ni-substituted YBa2Cu3O6.95 single crystals with Tc ranging from 92.5 K to 78 K. The fully symmetrical A1g channel and the B1g channel which is sensitive to the dx2-y2 gap maximum have been explored. The energy of the B1g pair-breaking peak remains constant under Ni doping while the energy of the A1g peak scales with Tc (EA1g/Tc=5). Our data show that the A1g peak tracks the magnetic resonance peak observed in inelastic neutron scattering yielding a key explanation to the long-standing problem of the origin the A1g peak.

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Y. Gallais, A. Sacuto, P. Bourges, Y. Sidis, A. Forget, D. Colson. 2002-08-08. Evidence for two distinct energy scales in the Raman spectra of YBa2(CuNi)O6.95. https://doi.org/10.1103/physrevlett.88.177401

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