Effective removal of global tilt from atomically-resolved topography images of vicinal surfaces with narrow terraces.

The main feature of vicinal surfaces of crystals characterized by the Miller indices (hhm) is rather small width (less than 10 nm) and substantially large length (more than 200 nm) of atomically-flat terraces. This makes difficult to apply standard methods of image processing and correct visualization of crystalline lattices at the terraces and multiatomic steps. Here we consider two procedures allowing us to minimize effects of both small-scale noise and global tilt of sample: (i) analysis of the difference of two Gaussian blurred images, and (ii) subtraction of the plane, whose parameters are determined by optimization of the histogram of the visible heights, from raw topography image.

Quantum-well and modified image-potential states in thin Pb(111) films: an estimate for the local work function.

Quantum-confined electronic states such as quantum-well states (QWS) inside thin Pb(111) films and modified image-potential states (IPS) above the Pb(111) films grown on Si(111) 7 × 7 substrate were studied by means of low-temperature scanning tunnelling microscopy (STM) and spectroscopy (STS) in the regime of constant current. By plotting the position of theth emission resonancesversusand extrapolating the linear fit for the dependence() in the high-limit towards= 0, we estimate the local work function for the Pb(111) film:≃ 3.8 ± 0.

The diode effect induced by domain-wall superconductivity.

On the basis of the phenomenological Ginzburg-Landau model we calculate the critical current of the domain-wall superconducting channel formed in flux-coupled superconductor/ferromagnet (S/F) hybrids in the presence of the nonuniform magnetic field of the domain walls. It is shown that the current-carrying ability in such S/F systems in the domain-wall superconducting state differs for the positive and negative directions of the injected current with respect to the parity-breaking vector, which is proportional to V x M and thus determined by the local magnetization vector M(r) in the ferromagnetic substrate. We demonstrate that in such S/F systems the realization of the so-called diode effect is possible for both laterally infinite and mesoscopic structures.

Domain-wall guided nucleation of superconductivity in hybrid ferromagnet-superconductor-ferromagnet layered structures.

Domain-wall superconductivity is studied in a superconducting Nb film placed between two ferromagnetic Co/Pd multilayers with perpendicular magnetization. The parameters of top and bottom ferromagnetic films are chosen to provide different coercive fields, so that the magnetic domain structure of the ferromagnets can be selectively controlled. From the dependence of the critical temperature Tc on the applied magnetic field H, we have found evidence for domain-wall superconductivity in this three-layered F/S/F structure for different magnetic domain patterns.