相关论文: Direct Correlation between Tc and CuO2 Bilayer Spa…

We report on the growth mechanism of YBa2Cu3O7-x (YBCO). Our study is based on the analysis of ultrathin, YBa2Cu3O7-x layers in c-axis oriented YBa2Cu3O7-x / PrBa2Cu3O7-x superlattices. We have found that the release of epitaxial strain in…

YBa2Cu3Ox, the first superconductor discovered with Tc higher than 77 K, is among the most complex cuprates having both CuO chains and plains in the structure. YBa2Cu3O7 (YBCO) exhibits slightly overdoped behavior and further doping is…

We report a temperature-dependent increase below 300 K of diffuse superlattice peaks corresponding to q_0 =(~2/5,0,0) in an under-doped YBa_2Cu_3O_6+x superconductor (x~0.63). These peaks reveal strong c-axis correlations involving the…

The temperature dependence of the relaxation dynamics in the bilayer thin film heterostructure composed of multiferroic BiFeO$_{3}$ (BFO) and superconducting YBa$_{2}$Cu$_{3}$O$_{7}$ (YBCO) grown on a (001) SrTiO$_{3}$ substrate is studied…

Superlattices of correlated oxides have been used to explore interfacial effects and to achieve additional control over the physical properties of individual constituents. In this work, we present a first-principles perspective of the…

Using high-energy diffraction we show that a 4-unit-cell superstructure, q0=(1/4,0,0), along the shorter Cu-Cu bonds coexists with superconductivity in optimally doped YBCO. A complex set of anisotropic atomic displacements on neighboring…

We examine the effect of CuO intergrowths on the superconductivity in epitaxial La_{2/3}Ca_{1/3}MnO_3/YBa_2Cu_3O_{7-\delta} (LCMO/YBCO) thin-film heterostructures. Scanning transmission electron microscopy on bilayer LCMO/YBCO thin films…

The oxygen deficiency $\delta$ in YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) plays a crucial role for affecting high-temperature superconductivity. We applied (coincident) Doppler broadening spectroscopy of the electron-positron annihilation line…

Heteroepitaxial superlattices of [YBa2Cu3O7(n)/ La0.67Ca0.33MnO3(m)]x, where n and m are the number of YBCO and LCMO monolayers and x the number of bilayer repetitions, have been grown with pulsed laser deposition on NdGaO3 (110) and…

Epitaxial bilayers of the high-temperature-superconductor YBa2Cu3O7-d (YBCO) and the ferromagnetic metal La0.67Ca0.33MnO3 (LCMO) were prepared by pulsed laser deposition on (110)-oriented SrTiO3 substrates, such that the CuO2 planes of YBCO…

Optimally doped YBCO (YBa$_{2}$Cu$_{3}$O$_{7}$) has a high critical temperature, at 92 K. It is largely believed that Cooper pairs form in YBCO and other cuprates because of spin fluctuations, the issue and the detailed mechanism is far…

To distinguish between the effects of strain and magnetism on the superconductivity in $c$-axis La$_{2/3}$Ca$_{1/3}$MnO$_3$/YBa$_2$Cu$_3$O$_{7-\delta}$ (LCMO/YBCO) heterostructures, we study perovskite/YBCO/perovskite thin films using…

We report measurements of the ab-plane superfluid density Ns (magnetic penetration depth, \lambda) of severely underdoped films of YBa2Cu3O6+x, with Tc's from 6 to 50 K. Tc is not proportional to Ns(0); instead, we find Tc ~ Ns^{1/2.3 +/-…

We report a large persistent photoconductivity (PPC) in oxygen reduced PLD grown YBa2Cu3O7-{\delta}/La2/3Ca1/3MnO3-y (YBCO/LCMO) superlattices scaling with the oxygen deficiency and being similar to that observed in single layer…

The normal and the superconducting state of two coupled CuO_2 layers in the High-T_c superconductors are investigated by using the bilayer Hubbard model, the FLEX approximation on the real frequency axis and the Eliashberg theory. We find…

The mechanism behind superconductivity suppression induced by Pr substitutions in YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) has been a mystery since its discovery: in spite of being isovalent to Y$^{3+}$ with a small magnetic moment, it is the…

X-ray photoemission spectroscopy has been used to investigate the depth dependent crystal structures and chemical compositions of sequentially chemical-etched YBa2Cu3O7-d (YBCO) ultrathin film superconductors. In the near-interface region…

The charge density wave in the high-temperature superconductor YBa$_2$Cu$_3$O$_{7-x}$ (YBCO) is now known to have two different ordering tendencies differentiated by their $c$-axis correlations. These correspond to ferro- (F-CDW) and…

Scanning tunneling spectroscopy (STS) studies reveal long-range (~100 nm) spatial homogeneity in optimally and underdoped superconducting YBa_2Cu_3O_{7-\delta} (YBCO) single crystals and thin films, and macroscopic spatial modulations in…

We investigate the strain response of underdoped HgBa$_2$CuO$_{4+\delta}$ (Hg1201), by synchrotron X-ray diffraction and corresponding simulations of thermal diffuse scattering. The compression in the crystallographic $a$ direction leads to…