Trends and Prospects of Tourism Development in Samara Region

The article considers current state, trends and prospects of tourism development in Samara Region

Charge manipulation and imaging of the Mn acceptor state in GaAs by Cross-sectional Scanning Tunneling Microscopy

An individual Mn acceptor in GaAs is mapped by Cross-sectional Scanning Tunneling Microscopy (X-STM) at room temperature and a strongly anisotropic shape of the acceptor state is observed. An acceptor state manifests itself as a cross-like feature which we attribute to a valence hole weakly bound to the Mn ion forming the (Mn$^{2+}3d^5+hole$) complex. We propose that the observed anisotropy of the Mn acceptor wave-function is due to the d-wave present in the acceptor ground state.Comment: Proceedings of the SIMD-4 conference. Hawaii, USA (December 1-5, 2003

Quantum phase transition in HTSC thick films: YBa2Cu 3O x, YBa2Cu3O x (5 % Ag-Doped) in a Strong Pulsed Magnetic Field up to 32 T at low temperatures (58-100 K), current densities and stress-effect

We have researched the influence of pulsed magnetic fields up to 32 T on the magneto-resistance of thick films (50 Mk) of YBa2Cu3O x and YBa2Cu3O x (5 % Ag-doped) that were produced from synthesized powders. (Figs. 1-9): concentrate with 6.85-6.9 % O2 and a tail fraction 6.5-6.6 % O2. We observed a linear plot at currents of more than 1 mA at 77 K in YBa2Cu 3O x (5 % Ag-doped) at B>5 T and in the concentrate YBa2Cu3O x samples with I=1 mA, T=68.2 K. Pulsed magnetic fields up to 32 T, at I=1 mA had practically no influence on the value of the magneto-resistance in the concentrate YBa2Cu 3O x specimens at T=57.9 K and up to 17 T for YBa 2Cu3O x (5 % Ag) at 77 K (Meissner effect). However, for B>17 T, YBa2Cu3O x (5 % Ag) at 77 K demonstrates a tendency toward lower resistance. In the presence to 10 pulses in a cyclic pulsed magnetic field of 32 T, there is a sharp change of magnetic properties of an HTSC that can lead to nontrivial changes in the transition temperature, due to the strong mechanic stresses, sharp change value structure, and because one of the phases becomes superconducting (Figs. 3A, 3B). The behavior of the magnetoresistance of S-N-S contacts in pulsed magnetic fields is described via the system's parallel resistance, R n, and the inductance, L S-N-S. Analysis of microscopic models of quantum phase transitions was made in a granular superconductor in an attempt to explain the results on the studied HTSC-films and to give a physical interpretation to the deduced parameters of some experiments on the basis of "spin (vortex) glass" (vortex ice). © 2012 Springer Science+Business Media New York