Related papers: Electric field-induced oxygen vacancies in YBa2Cu3…
The transition from insulator to conductor can be achieved in some materials but requires modification of both the arrangement of atoms and their electronic configurations. This is often achieved by doping. Here we reveal a mechanism the…
YBa2Cu3O7-x/La0.67Ca0.33MnO3 ferromagnetic/superconducting interfaces are analyzed by scanning transmission electron microscopy and electron energy loss spectroscopy with monolayer resolution. We demonstrate that extensive charge transfer…
The superconducting phase transition in YBa$_{2}$Cu$_{3}$O$_{7-\textit{$\delta $}}$(YBCO) thin film samples doped with non-superconducting nanodot impurities of CeO$_{2}$ are the focus of recent high-temperature superconductor studies.…
Cu$_2$O has appealing properties as an electrode for photo-electrochemical water splitting, yet its practical performance is severely limited by inefficient charge extraction at the interface. Using hybrid DFT calculations, we investigate…
We report on the growth and characterization of ultrathin YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) films on MgO (110) substrates, which exhibit superconducting properties at thicknesses down to 3 nm. YBCO nanowires, with thicknesses down to 10 nm…
The microwave conductivity of an ultra-pure single crystal of YBa$_2$Cu$_3$O$_{6.50}$ has been measured deep in the superconducting state as a continuous function of frequency from $0.5\to20$ GHz. Conductivity spectra were first measured at…
Compelling efforts to improve the critical temperature ($T_{c}$) of superconductors have been made through high-pressure application. Understanding the underlying mechanism behind such improvements is critically important, however, much…
The proposed switching mechanism is based on an electronically-induced metal-insulator transition occurring in conditions of the excess non-equilibrium carrier density under the applied electric field. First, this mechanism is developed on…
Electron transport is studied in surface oxidized single-crystal copper thin films with a thickness of up to 5.6 nm by applying density functional theory and density functional tight binding methods to determine electron transport…
The effect of high tensile strain and low dimensionality on the magnetic and electronic properties of CaMnO$_3$ ultrathin films, epitaxially grown on SrTiO$_3$ substrates, are experimentally studied and theoretically analyzed. By means of…
The detection of quantum oscillations in the electrical resistivity of YBa2Cu3O6.5 provides direct evidence for the existence of Fermi surface pockets in an underdoped cuprate. We present a theoretical study of the electronic structure of…
Quasi-two-dimensional electron systems (q-2DES) are formed in various hetero-structures, including oxide interfaces. Oxygen vacancies (OVs) in oxides like $\mathrm{SrTiO_3}$ are known to produce electronic carriers. A novel way to produce…
X-ray absorption spectra of oxide systems Ba_{1-x}K_xBiO_3 and BaPbO_3 above Bi- and Pb-L3 absorption edges were investigated. It was shown that oxygen ions move in double-well potential and their oscillations are correlated with charge…
We investigate the microscopic mechanisms behind the stabilization of three-dimensional (3D) charge order by Pr doping in YBa$_2$Cu$_3$O$_7$ (YBCO7). Density-functional-theory calculations locate the lowest-energy Pr superlattices for both…
Optical conductivity spectra of cubic pyrochlore $Y_{2-x} Bi_x Ru_2 O_7$ (0.0$\leq ${\it x}$\leq $2.0) compounds are investigated. As a metal-insulator transition (MIT) occurs around {\it x}$=$0.8, large spectral changes are observed. With…
Current-voltage characteristics of planar junctions formed by an epitaxial c-axis oriented YBa2Cu3O7-x thin film micro-bridge and Ag counter-electrode were measured in the temperature range from 4.2 K to 300 K. A hysteretic behavior related…
One of the basic assumptions in organic field-effect transistors, the most fundamental device unit in organic electronics, is that charge transport occurs two-dimensionally in the first few molecular layers near the dielectric interface.…
We study the ferroelectric stability and surface structural properties of an oxygen-terminated hexagonal YMnO$_3$ ultra-thin film using density functional theory. Under an open circuit boundary condition, the ferroelectric state with the…
High-temperature superconductivity occurs as copper oxides are chemically tuned to have a carrier concentration intermediate between their metallic state at high doping and their insulating state at zero doping. The underlying evolution of…
We are examining the possibility of the formation of charge order in the high-temperature superconductor $\mathrm{YBa_2Cu_3O_{7-\delta}}$ (YBCO) due to interaction between the charged oxygen vacancies or di-vacancies. The molecular dynamics…