Related papers: Coupling between planes and chains in YBa2Cu3O7 : …
Ab initio band theory including correlations due to intra-atomic repulsion is applied to study charge disproportionation and charge- and spin-ordering in insulating Na$_{0.5}$CoO$_2$. Various ordering patterns (zigzag and two striped) for…
An intact CuO$_2$ plane is widely believed to be a prerequisite for the high-$T_c$ superconductivity in cuprate superconductors. However, an exception may exist in the superconducting Ba$_2$CuO$_{3+\delta}$ materials where CuO chains play a…
In this paper we study the order parameter and density of states near a grain boundary between two $d_{x^2-y^2}$ superconductors. We examine broken time reversal symmetry near the interface. In particular we show that, under suitable…
All underdoped high-temperature cuprate superconductors appear to exhibit charge density wave (CDW) order, but both the underlying symmetry breaking and the origin of the CDW remain unclear. We use X-ray diffraction to determine the…
A parameter-free statistical model is used to study multiplicity signatures for coherent production of charged-pairs of parabosons of order p=2 in comparison with those arising in the case of ordinary bosons, p=1. Two non-negative real…
Controlling matter to simultaneously support multiple coupled properties is of fundamental and technological importance. For example, the simultaneous presence of magnetic and ferroelectric orders in multiferroic materials leads to enhanced…
Analysis of the a-b plane optical conductivity $\sigma_{ab}$ for both twinned and untwinned YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ as a function of temperature and doping shows that below a well defined temperature T*, a dip in the spectrum…
Recently, Rourke et al. reported point-contact spectroscopy results on the heavy-fermion superconductor CeCoIn$_5$ [1]. They obtained conductance spectra on the c-axis surfaces of CeCoIn$_5$ single crystals. Their major claims are two-fold:…
We study the superconducting phase with two component order parameter scenario, such as, $d_{x^2-y^2} + e^{i\theta}s_{\alpha}$, where $\alpha = xy, x^2+y^2$. We show, that in absence of orthorhombocity, the usual $d_{x^2-y^2}$ does not mix…
The polarized femtosecond spectroscopies obtained from well characterized (100) and (110) YBa2Cu3O7-\delta thin films are reported. This bulk-sensitive spectroscopy, combining with the well-textured samples, serves as an effective probe to…
The orbital component of the order parameter in the cuprate high-Tc cuprate superconductors is now well established, in large part because of phase sensitive tests. Although it would be desirable to use such tests on other unconventional…
In this work we consider two models of two dimensional discrete systems subjected to three different types of coupling and analyse systematically the performance of each in realising synchronised states.We find that linear coupling…
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…
Transport measurements provide important characterizations of the nature of stripe order in the cuprates. Initial studies of systems such as La(1.6-x)Nd(0.4)Sr(x)CuO(4) demonstrated the strong anisotropy between in-plane and c-axis…
We derive general constraints on order and disorder parameters in Ising symmetric spin chains. Our main result is a theorem showing that every gapped, translationally invariant, Ising symmetric spin chain has either a nonzero order…
We present a comprehensive study of the crystal structure, magnetic structure, and microscopic magnetic model of (CuBr)LaNb2O7, the Br analog of the spin-gap quantum magnet (CuCl)LaNb2O7. Despite similar crystal structures and spin…
Starting from a model Hamiltonian for the normal state of the topological insulator Bi2Se3, we construct a pseudospin basis for the single-particle wavefunctions. Considering weak superconducting pairing near the Fermi surface, we express…
The organization of dopants in high temperature superconductors provides complex topological geometries that controls superconducting properties. This makes the study of dopants spatial distribution of fundamental importance. The mobile…
The candidate magnetoelectric Pb3Mn7O15 has a structure consisting of 1/3 filled Kagome layers linked by ribbons of edge-sharing octahedra in the stacking direction. Previous reports have indicated a complex hexagonal-orthorhombic…
Recent results on electrons and holes doped CuO 2 planes confirm the marked covalency of CuO bonding, suggesting a band picture of long and short range antiferromagnetism. The maxima of superconductive T c versus doping can be related to…