The electron-boson spectral density function of underdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ and YBa$_2$Cu$_3$O

Jungseek Hwang

doi:10.1103/PhysRevB.83.014507

paper

The electron-boson spectral density function of underdoped Bi $_{2}$ Sr $_{2}$ CaCu $_{2}$ O $_{8 + δ}$ and YBa $_{2}$ Cu $_{3}$ O

arXiv:1103.5129 · doi:10.1103/PhysRevB.83.014507

Abstract

We investigate the electron-boson spectral density function, $I^{2} χ (ω, T)$ , of CuO $_{2}$ plane in underdoped Bi $_{2}$ Sr $_{2}$ CaCu $_{2}$ O $_{8 + δ}$ (Bi-2212) and underdoped YBa $_{2}$ Cu $_{3}$ O $_{6.50}$ (Y-123) using the Eliashberg formalism. We apply a new (in-plane) pseudogap model to extract the electron-boson spectral function. For extracting the spectral function we assume that the spectral density function consists of two components: a sharp mode and the broad Millis-Monien-Pines (MMP) mode. We observe that both the resulting spectral density function and the intensity of the pseudogap show strong temperature dependences: the sharp mode takes most spectral weight of the function and the peak position of the sharp mode shifts to lower frequency and the depth of pseudogap, $1 - N ~ (0, T)$ , is getting deeper as temperature decreases. We observe also that the total spectral weight of the electron-boson density and the mass enhancement coefficient increase as temperature decreases. We estimate fictitious (maximum) superconducting transition temperatures, $T_{c} (T)$ , from the extracted spectral functions at various temperatures using a generalized McMillan formula. The estimated (maximum) $T_{c}$ also shows a strong temperature dependence; it is higher than the actual $T_{c}$ at all measured temperatures and decreases with temperature lowering. Since as lowering temperature the pseudogap is getting stronger and the maximum $T_{c}$ is getting lower we propose that the pseudogap may suppress the superconductivity in cuprates.

8 pages, 6 figures

The electron-boson spectral density function of underdoped Bi $_{2}$ Sr $_{2}$ CaCu $_{2}$ O $_{8 + δ}$ and YBa $_{2}$ Cu $_{3}$ O

Abstract

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Cited by in corpus (13)

The electron-boson spectral density function of underdoped Bi2​Sr2​CaCu2​O8+δ​ and YBa2​Cu3​O

Abstract

References in corpus (6)

Cited by in corpus (13)

The electron-boson spectral density function of underdoped Bi $_{2}$ Sr $_{2}$ CaCu $_{2}$ O $_{8 + δ}$ and YBa $_{2}$ Cu $_{3}$ O