Related papers: Thermally-activated current transport in MgB_2 fil…
Identifying the microscopic processes that limit conductivity is essential for understanding correlated and quantum-critical states in quantum materials. In twisted bilayer graphene (TBG) and other twist-controlled materials, the…
The trigonal compound EuMg2Bi2 has recently been discussed in terms of its topological band properties. These are intertwined with its magnetic properties. Here detailed studies of the magnetic, thermal, and electronic transport properties…
We have systematically investigated the electrical transport properties of polycrystalline TaN$_x$ ($0.83$$\lesssim$$x$$\lesssim$1.32) films with rocksalt structure from 300 down to 2 K. It is found that the conductivity varies linearly…
We investigate experimentally the electric transport at the insulating side of the superconductor to insulator transition in thin TiN-films. At temperatures T > 50 mK we observe an Arrhenius-type conductance, with an activation energy…
Critical fields of four MgB2 thin films with a normal state resistivity ranging from 5 to 50 mWcm and Tc from 29.5 to 38.8 K were measured up to 28 T. Hc2(T) curves present a linear behavior towards low temperatures. Very high critical…
Superconducting MgB2 thin films were prepared on 50-micrometer-thick, flexible polyamide Kapton-E foils by vacuum co-deposition of Mg and B precursors with nominal thickness of about 100 nm and a special ex-situ rapid annealing process in…
An antiferromagnetic transition is observed in single crystal EuRh2As2 at a high temperature T_N = 47 K compared to the ferromagnetic Weiss temperature theta = 12 K. We show that this is, surprisingly, consistent with mean field theory. A…
The electrical conductivity induced near the superconducting transition by thermal fluctuations was measured in different granular aluminum films. The seemingly anomalous behavior at high reduced temperatures and magnetic fields is…
Spatially resolved transport in two-dimensional quantum materials can reveal dynamics which is invisible in conventional bulk transport measurements. We predict striking patterns in spatially inhomogeneous transport just above the critical…
We report on isofield magnetization curves obtained as a function of temperature in two single crystals of $Ba_{1-x}K_xFe_2As_2$ with superconducting transition temperature $T_c$=28K and 32.7 K. Results obtained for fields above 20 kOe show…
We have grown MgB2 films in a postannealing process. Precursors were prepared on Al2O3(0001) substrates by codeposition of Mg and MgB2 using pulsed laser deposition technique. Superconducting MgB2 thin films were obtained via an ex situ…
Thermal fluctuation conductivity for a layered superconductor in perpendicular magnetic field is treated in the frame of the self-consistent Hartree approximation for an arbitrarily strong in-plane electric field. The simultaneous…
The critical current density of four MgB2 samples was measured inductively and for one of them also by transport. Pure phased and dense bulk samples yield a critical current density which in value, as well as in its magnetic field and…
Applying a magnetic field to a solid changes its thermal-transport properties. Although such magneto-thermal-transport phenomena are usually small effects, giant magneto-thermal resistance has recently been observed in spintronic…
It is shown that the temperature of the resistive transition $T_r$ of a superconducting film can be increased by a thin superconducting or normal overlayer. For instance, deposition of a highly conductive thin overlayer onto a dirty…
The angular and temperature dependence of the upper critical field Hc2 in MgB2 was determined from torque magnetometry measurements on single crystals. The Hc2 anisotropy gamma_H was found to decrease with increasing temperature, in…
Transport current values of 7.5 x 104 A/cm2 at 4.2 K and self-field are reported for MbB2-based tapes. MgB2 strands were formed by directly filling commercially available MgB2 powder into Nb-lined, monel tubes and wire drawing. The wires…
Frequency-dependent terahertz conductivities of La$_{2-x}$Sr$_x$CuO$_4$ thin films with various carrier concentrations were investigated. The imaginary part of the complex conductivity considerably increased from far above a zero-resistance…
We report the fabrication of MgB2 with bulk superconducting properties by conventional solid state methods at temperatures as low as 550 C. Mg deficiencies of the type Mg1-xB2 were tested. Tc was found to decrease by about 1K at large x,…
The in-plane thermal conductivity kappa(T) and electrical resistivity rho(T) of the heavy-fermion metal YbRh2Si2 were measured down to 50 mK for magnetic fields H parallel and perpendicular to the tetragonal c axis, through the field-tuned…