相关论文: Fluctuation Magnetoconductance in MgB2
The rich structure that we observe in molecular clouds is due to the interplay between strong magnetic fields and supersonic (turbulent) velocity fluctuations. The velocity fluctuations interact with the magnetic field, causing it too to…
The specific heat of polycrystalline Mg$^{11}$B$_{2}$ has been measured with high resolution ac calorimetry from 5 to 45 K at constant magnetic fields. The excess specific heat above T$_{c}$ is discussed in terms of Gaussian fluctuations…
The fluctuation conductivity $\sigma_{\rm s}$ in bulk superconductors with non s-wave pairing and with nonmagnetic disorder of strength $D$ is studied at low $T$ and within the Gaussian approximation. It is shown by assuming a quasi…
A theory of fluctuations in two-band superconductor MgB$_{2}$ is developed. Since the standard Ginzburg-Landau (GL) approach fails in description of its properties, we generalize it basing on the microscopic theory of a two-band…
High-density bulk materials of a newly discovered 40K intermetallic MgB2 superconductor were prepared by high pressure sintering. Superconducting transition with the onset temperature of 39K was confirmed by both magnetic and resistive…
We report high-resolution specific heat data on a high-quality single crystal of the classical superconductor V3Si, which reveal tiny lambda-shape anomalies appearing superimposed onto the BCS specific heat jump at the superconducting…
We report the effect of the \emph{ab}-plane magnetic field $B$ up to $8\,\mathrm{T}$ on the resistivity $\rho(T)$ and fluctuation conductivity $\sigma'(T)$ in YBa$_2$Cu$_3$O$_{7-\delta}$ thin films. As expected, up to $\sim 2.5\,\mathrm{T}$…
We demonstrate the presence of ferromagnetic (FM) fluctuations in the superconducting and non-superconducting heavily overdoped regimes of high-temperature superconducting copper oxides, using (Bi,Pb)_2_Sr_2_CuO_6+delta_ (Bi-2201) single…
Superconducting fluctuations (SF) in SmFeAsO$_{0.8}$F$_{0.2}$ (characterized by superconducting transition temperature $T_{c} \simeq 52.3$ K) are investigated by means of isothermal high-resolution dc magnetization measurements. The…
Magnetization and 63Cu NMR-NQR relaxation measurements are used to study the superconducting fluctuations in YBa2Cu3O6+x (YBCO) oriented powders. In optimally doped YBCO the fluctuating negative magnetization M_{fl}(H,T) is rather well…
The study of excess conductivity $\sigma'(T)$ in the textured polycrystalline FeAs-based superconductor $EuFeAsO_{0.85}F_{0.15}$ ($T_c = 11\, K$) prepared by the solid state synthesis is reported. The $\sigma'(T)$ analysis has been…
In highly anisotropic cuprate superconductors it is generally accepted that the reversible magnetization vector, M, is essentially perpendicular to the superconducting CuO2 layers in a wide range of crystal orientations with respect to the…
Electric and magnetic characterization of NbSe2 single crystals is first presented in detail. Then, some preliminary measurements of the fluctuation-diamagnetism (FD) above the transition temperature Tc are presented. The moderate uniaxial…
Spin fluctuations are reported near the magnetic field driven quantum critical point in YbRh2Si2. On cooling, ferromagnetic fluctuations evolve into incommensurate correlations located at q0=+/- (delta,delta) with delta=0.14 +/- 0.04 r.l.u.…
Paraconductivity of the optimally K-doped SrFe2As2 superconductor is investigated within existing fluctuation mechanisms. The in-plane excess conductivity has been measured in high quality single crystals, with a sharp superconducting…
Magnetoconductivity of the disordered two- and three-dimensional superconductors is addressed at the onset of superconducting transition. In this regime transport is dominated by the fluctuation effects and we account for the interaction…
We extract the quantum conductance fluctuations and study its magnetic field dependence in the gate-dependent transport of the topological electrons in bulk-insulating BiSbTeSe2 devices. While increasing the magnetic field from 0 to 12…
We study fluctuation conductivity in a single crystal of BaFe$_{1.9}$Ni$_{0.1}$As$_2$ superconductor ($T_c$ = 20 K) as a function of temperature and applied magnetic field. Magneto-conductivity curves, $\Delta \sigma$ vs. $T$, were analyzed…
We measured the static uniform spin susceptibility of Ba(Fe$_{1-x}$Rh$_x$)$_2$As$_2$ iron-based superconductors, over a broad range of doping ($0.041\leq x\leq 0.094$) and magnetic fields. At small fields ($H \le$ 1 kOe) we observed, above…
We summarize the present status of the theories of spin fluctuations in dealing with the anomalous or non-Fermi liquid behavior and unconventional superconductivity in strongly correlated electron systems around their magnetic instabilities…