Electronic crossover in the overdoped high-temperature(Y,Ca)Ba2Cu3Oy

Abstract

The electronic Raman scattering in overdoped ͑Y,Ca͒Ba 2 Cu 3 O y was investigated with changing hole concentration in the superconducting state. It was found that the superconducting responses such as the pairbreaking peaks in the A 1g and B 1g spectra and the anisotropy of the pair-breaking peak in XX and YY polarizations radically change at around the carrier doping p = 0.19. Since both a-and c-axis resistivities strongly suggest the closing of pseudogap at p ϳ 0.18, the observed change at p = 0.19 in the superconducting Raman response is attributed to the electronic crossover due to the collapse of the pseudogap.

Collapse of the Normal-State Pseudogap at a Lifshitz Transition in theBi2Sr2CaCu2OBenhabib1, Sacuto2, Civelli3 et al. 2015Phys. Rev. Lett.10118860View full textAdd to dashboardCite

“…[22]). studies [23,[25][26][27][28][29][30][31], However, the crucial finding of the current work is that this trend changes and the BU j response starts to decrease beyond 0.22 doping.…”

Electronic and phononic Raman scattering in detwinnedYBa2Cu3O6.95andBakr1, Schnyder2, Klam3 et al. 2009Phys. Rev. B343340View full textAdd to dashboardCite

“…3͒, but our model calculations suggest that this is a consequence of the s-wave admixture to the gap, 3 obviating the need to introduce quantum interference between scattering from chains and planes. 51,52 …”

Electronic Raman spectra of slightly underdopedYBa2Cu3O7−δ: Unusual behavior of antinodal electrons

“…For example, in the underdoped YBa 2 Cu 3 O 7−␦ ͑YBCO͒ with T c = 60 K, no superconductivity-induced feature is observed in the B 1g spectrum 4,5 while in the overdoped YBCO, the polarization dependence of the pair-breaking peak energy is lost. 6,7 According to the results of angle-resolved photoemission spectroscopy ͑ARPES͒ that demonstrate a d-wavelike momentum dependence of the gap, 8,9 the Raman response to the pseudogap is expected to show a similar polarization dependence to that for the SC gap. However, in the underdoped YBCO, which is a typical pseudogap system, the B 1g spectrum does not show any gap-related features 5 while the B 2g ͑Ref.…”