Out-of-plane dielectric constant and insulator-superconductor transition in Bi₂Sr₂Dy_1-xEr_xCu₂O₈single crystals

Abstract

The out-of-plane dielectric constant of the parent insulator of the high-temperature superconductor Bi2Sr2Dy1-xErxCu2O8 was measured and analysed from 80 to 300 K in the frequency range of 106-109 Hz. All the samples were found to show a fairly large value of 10-60, implying some kind of charge inhomogeneity in the CuO2 plane. Considering that the superconducting sample Bi2Sr2Ca0.75Pr0.25Cu2O8 also shows a similar dielectric constant, the charge inhomogeneity plays an important role in the insulator-superconductor transition.

Thermoelectric Properties of Layered Pd Oxide R2PdO4(R = La, Nd, Sm, and Gd)

“…A similar example is seen in the parent insulator of high-temperature superconductor Bi 2 Sr 2 Er 1−x Dy x Cu 2 O 8+δ , in which the carrier density systematically decreases with increasing x. [15] Let us analyze the resistivity and thermopower more quantitatively. As mentioned above, R 2 PdO 4 is a nearly undoped semiconductor with an energy gap between the d x 2 −y 2 and d 3z 2 −r 2 bands.…”

Anomalous dielectric response in the dimer Mott insulatorκ−(BEDT-TTF)2Cu2(CNAbdel‐Jawad1, Terasaki2, Sasaki3 et al. 2010Phys. Rev. B179231800View full textAdd to dashboardCite

“…We should note that the temperature and frequency dependence of ε is similar between the in-and cross-plane directions of layered materials, so that the ac response of a two-dimensional dielectric material can be discussed from the cross-plane measurement at least qualitatively. 13 The magnitudes of ε are even close in some materials such as LuFe 2 O 4 .…”

In-plane thermoelectric properties of heavily underdoped high-temperature superconductor Bi2Sr2CaCu2O8+δ

“…The large pseudogap was later verified in angle-resolved photoemission spectroscopy, in which a two-gap structure was clearly seen [19]. Takayanagi et al [20] found that the dielectric constant does not diverge toward the metal-insulator transition, and discussed this phenomenon in terms of an electronic mixture of the pseudogap phase and the superconducting phase.…”