Related papers: Optical studies of gap, hopping energies and the A…

An exact study of charge-spin separation, pairing fluctuations and pseudogaps is carried out by combining the analytical eigenvalues of the four-site Hubbard clusters with the grand canonical and canonical ensemble approaches in a…

We present a theory of the electronic and optical properties of a charged artificial benzene ring (ABR). The ABR is described by the extended Hubbard model solved using exact diagonalization methods in both real and Fourier space as a…

$\mathrm{CuO}$ atomic thin monolayer ($\mathrm{mlCuO}$) was synthesized recently. Interest in the $\mathrm{mlCuO}$ is based on its close relation to $\mathrm{CuO_2}$ layers in typical high temperature cuprate superconductors. Here, we…

We present a study of the superconducting energy gap performed with point contact spectroscopy in a single crystal of the superconductor Zr0:97V0:03B2. We determined the size and evolution with temperature of the energy gap, the transition…

We perform first-principles calculation to study the electronic structure of HgBa$_{2}$Ca$_{n-1}$Cu$_{n}$O$_{2n+2+x}$ copper oxides up to $n = 6$ for the undoped parent compound $(x = 0)$ and up to $n = 3$ for the doped compound $(x > 0)$…

We compare theoretical results for electron spin resonance (ESR) properties of the Heisenberg-Ising Hamiltonian with ESR experiments on the quasi-one-dimensional magnet Cu(py)$_2$Br$_2$ (CPB). Our measurements were performed over a wide…

Thin films of VO$_2$ on different substrates, Al$_2$O$_3$ and SiO$_2$/Si, have been prepared and characterized from room temperature up to 360 K. From the band structure in the rutile metallic phase and in the monoclinic insulating phase…

We have measured the near-normal reflectance of Tl2Ba2CaCu2O8 (Tl2212) for energies from 0.1 to 4.0 eV at room temperature and used a Kramers-Kronig analysis to find the complex, frequency dependent dielectric function, from which the…

We have studied the structural, magnetic properties, and electronic structure of the compound InCuPO5 synthesized by solid state reaction method. The structure of InCuPO5 comprises of S = 1/2 uniform spin chains formed by corner-shared CuO4…

We present a holographic calculation of energy correlators in a simple model of confinement based on a warped extra dimension with an IR brane. For small distances we reproduce the constant correlators of a strongly-coupled conformal field…

Correlation effects of an electron gas in an external potential are derived using an Effective Action functional method. Corrections beyond the random phase approximation (RPA) are naturally incorporated by this method. The Effective Action…

We present a detailed calculation of the magnetic couplings between nearest-neighbor and next-nearest-neighbor coppers in the edge-sharing geometry, ubiquitous in many cuprates. In this geometry, the interaction between nearest neighbor…

Starting from the quasi one-dimensional kinetic energy of the d_{yz} and d_{zx} bands we derive a bosonized description of the correlated electron system in Sr_2RuO_4. At intermediate coupling the magnetic correlations have a quasi…

Electronic properties of the Si(111)-$7\times 7$ surface are studied using four- and two-probe conductivity measurements and tunneling spectroscopy. We demonstrate that the temperature dependence of the surface conductivity corresponds to…

Bulk-sensitive hard x-ray photoemission spectroscopy (HAXPES) reveals for as-grown epitaxial films of half-metallic ferromagnetic CrO2(100) a pronounced screening feature in the Cr 2p3/2 core level and an asymmetry in the O 1s core level.…

The solid-state reaction was used to synthesize CoO2 nanostructured material. Cobalt nitrate tetrahydrate and sodium oxide (NaOH) were combined to produce CoO2 nanostructured material. The three synthesized working electrodes were each…

Using first-principles electronic structure calculations based on the Nth order muffin tin orbital (NMTO)-downfolding technique, we derived the low-energy spin model for CuTe2O5. Our study reveals that this compound is a 2D coupled…

We present a new paradigm for the design of exchange-correlation functionals in density-functional theory. Electron pairs are correlated explicitly by means of the recently developed second order Bethe-Goldstone equation (BGE2) approach.…

We use the constrained random phase approximation (cRPA) method to calculate the Hubbard $U$ parameter in four one-dimensional magnetic transition metal atom oxides of composition XO$_2$ (X = Mn, Fe, Co, Ni) on Ir(100). In addition to the…

Using a combination of X-ray absorption spectroscopy experiments with first principle calculations, we demonstrate that insulating KCuO_2 contains Cu in an unusually-high formal-3+ valence state, the ligand-to-metal (O to Cu) charge…