Related papers: Fluctuations Indicate Strong Interlayer Coupling i…

Bulk superconductor samples of YBa2Cu3-xCoxO7-{\delta} with x = 0, 0.01, 0.03, 0.05 are synthesized by solid-state reaction route. Both x-ray diffraction and electron microscopy have been employed to study the phase identification,…

We study the phase-locking transition of two coupled low-dimensional superfluids, either two-dimensional superfluids at finite temperature, or one-dimensional superfluids at zero temperature. We find that the superfluids have a strong…

We investigate superfluid phase transitions of asymmetric nuclear matter at finite temperature ($T$) and density ($\rho$) with a low proton fraction ($Y_{\rm p} \le 0.2$) which is relevant to the inner crust and outer core of neutron stars.…

Recent measurements on extremely-underdoped YBa2Cu3O6+y [Phys. Rev. Lett. 99, 237003 (2007)] have allowed the critical temperature (T_c), superfluid density [rho_0 (T << T_c)] and dc conductivity [sigma_dc (T ~ T_c)] to be determined for a…

Critical fluctuations have been studied in the microwave conductivity of Bi_2Sr_2CaCu_2O_(8+\delta), Bi_2Sr_2Ca_2Cu_3O_(10+delta), and YBa_2Cu_3O_(7-delta) thin films above T_c. It is found that a consistent analysis of the real and…

At the beginning of cuprate superconductors, the interlayer tunneling (ILT) and Lawrence-Doniach (L-D) models, which connect the CuO planes by Josephson coupling were considered the leading theoretical proposals for these materials.…

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…

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…

We present a combined growth and transport study of superconducting single-crystalline NdO$_{0.5}$F$_{0.5}$BiS$_2$. Evidence of two-dimensional superconductivity with significant phase fluctuations of preformed Cooper pairs preceding the…

One of the hallmarks of the Berezinskii-Kosterlitz-Thouless (BKT) transition in two-dimensional (2D) superconductors is the universal jump of the superfluid density, that can be indirectly probed via the non-linear exponent of the…

We propose an explanation of the superconducting transitions discovered in the heavy fermion superlattices by Mizukami et al. (Nature Physics 7, 849 (2011)) in terms of Berezinskii-Kosterlitz-Thouless transition. We observe that the…

The optical properties of the iron-chalcogenide superconductor K{0.8}Fe{2-y}Se2, with a critical temperature Tc = 31 K, have been measured over a wide frequency range in the a-b planes above and below Tc. The conductivity is incoherent at…

We describe high-Tc superconductivity in layered materials within a BCS theory as a BEC of massless-like Cooper pairons satisfying a linear dispersion relation, and propagating within quasi-2D layers of finite width defined by the charge…

A Ginzburg-Landau approach to fluctuations of a layered superconductor in a magnetic field is used to show that the interlayer coupling can be incorporated within an interacting self-consistent theory of a single layer, in the limit of a…

The magnetic oscillations in YBCO high-temperature superconductors have been widely studied over the last decade and consist of three equidistant low frequencies with a central frequency several times more intense than its two shoulders.…

Superconductivity in granular films is controlled by the grain size and the inter-grain coupling. In a two-component granular system formed by a random mixture of a normal metal (N) and a superconductor (S), the superconducting nano-grains…

The coupling between superconductors and a quantum critical liquid that is nearly superconducting provides natural interpretation for the Josephson effect over unexpectedly long junctions, and the remarkable stripe-spacing dependence of the…

We report on the new non--linear optical signatures of quantum phase transitions in the high-temperature superconductor YBCO, observed through high harmonic generation. While the linear optical response of the material is largely unchanged…

In the pursuit of higher critical temperature of superconductivity, quasi-flat electronic bands and van Hove singularities in two dimensions (2D) have emerged as a potential approach to enhance Cooper pairing on the basis of mean-field…

The optical properties of single crystals of YBa_2Cu_3O_{6+x} have been examined along the c axis above and below the critical temperature (T_c) for a wide range of oxygen dopings. The temperature dependence of the optically-determined…