Related papers: Electric field-induced oxygen vacancies in YBa2Cu3…
Thin films of the superconductor YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) were modified by low-energy light-ion irradiation employing collimated or focused He$^+$ beams, and the long-term stability of irradiation-induced defects was investigated.…
We study the spin fluctuation dynamics of Cu-O chains in the oxygen deficient planes of YBa(2)Cu(3)O(6+x). The chains are described by a model including antiferromagnetic interactions between the spins and Kondo-like scattering of the…
The influence of the electric field and electric current on the behavior of oxygen vacancies (VOs) in TiO2 anatase was investigated with Scanning Tunneling Microscopy (STM). At the anatase (101) surface VOs are not stable; they migrate into…
The electrical transport properties of ultrathin YBCO films have been modified using an electric double layer transistor configuration employing an ionic liquid. The films were grown on SrTiO3 substrates using high pressure oxygen…
We apply density functional theory and the augmented spherical wave method to analyze the electronic structure of V2O3 in the vicinity of an interface to Al2O3. The interface is modeled by a heterostructure setup of alternating vanadate and…
Upon reduction of the film thickness we observe a metal-insulator transition in epitaxially stabilized, spin-orbit coupled SrIrO$_3$ ultrathin films. By comparison of the experimental electronic dispersions with density functional theory at…
We report a study of the basal-plane anisotropy of the superfluid density in underdoped YBa$_{2}$Cu$_{4}$O$_{8}$ (Y124), showing the effects of both the CuO$_{2}$ planes and the fully occupied CuO chains. From small-angle neutron scattering…
Transport in electronic devices based on high-Tc superconductors depends critically on the charge redistribution at interfaces, since the band structure is modified on a local scale. Using the density functional theory approach for relaxed…
We report on a photo-induced transient state of YBa2Cu2O6+x in which transport perpendicular to the Cu-O planes becomes highly coherent. This effect is achieved by excitation with mid-infrared optical pulses, tuned to the resonant frequency…
The electronic structure of YBa2Cu3O6+x and La2-xSrxCuO4 for various values of x has been investigated using hard x-ray photoemission spectroscopy. The experimental results establish that the cleaving of YBa2Cu3O6+x compounds occurs…
We measured the terahertz (THz) complex conductivity of Ca doped YBa_{2}Cu_{3}O_{7-\delta} thin films in the frequency range of 0.1 to 3 THz (3 to 100 cm^{-1}) and at a temperature range of 20 to 300 K. The films were measured using both…
Band structure calculations are presented for large supercells of Ba$_2$CuO$_4$ (BCO) with O-vacancies in planar or apic al positions, and of superoxygenated La$_2$CuO$_4$ (LCO) with oxygen interstitials in the La$_2$O$_2$ layers. It is…
We study the behaviour of the electronic chemical potential in YBa2Cu3O near the superconducting transition using the spin-wave exchange theory of pairing. We find that the experimental value of the jump in the temperature derivative of the…
A self-consistent model is developed for the surface and bulk states of thin Y_{1-y}Ca_yBa_2Cu_3O_{7-\delta} (YCBCO) films. The dispersions of the chain and plane layers are modelled by tight-binding bands, and the electronic structure is…
Recording field ion microscope images under field evaporating conditions and subsequently reconstructing the underlying atomic configuration, called three-dimensional field ion microscopy (3D-FIM) is one of the few techniques capable of…
Vortex entry into (110) oriented YBa$_2$Cu$_3$O$_{7-x}$ films has been studied by tunneling into Andreev - Saint-James bound states, whose energy is shifted by surface currents. At low temperatures, the characteristic field for vortex entry…
Oxygen vacancies in nickelates are known to introduce a variety of emergent phenomena and are considered to significantly affect conductivity. Few studies have examined real-space evidence for oxygen vacancies on the surface, particularly…
We have studied a three-unit-cell-thick YBa2Cu3O7-x (YBCO) superconducting film grown on a slightly vicinal SrTiO3 substrate that was polished from the (001) plane by a small miscut angle (less than 0.5 degrees). This produced, on its…
Detailed measurements of the critical current density jc of YBa2Cu3O7 films grown by pulsed laser deposition reveal the increase of jc as function of the filmthickness. Both this thickness dependence and the field dependence of the critical…
We studied the tunneling density of states in YBCO films under strong currents flowing along node directions. The currents were induced by fields of up to 32.4T parallel to the film surface and perpendicular to the $CuO_{2}$ planes. We…