Related papers: Dendritic magnetic instability in superconducting …
According to the crystal structure of MgB$_{2}$ and band structure calculations quasi-two-dimensional (2D) boron planes are responsible for the superconductivity. We report on critical fields and resistance measurements of 30 nm thick…
This review paper illustrates the main normal and superconducting state properties of magnesium diboride, a material known since early 1950's, but recently discovered to be superconductive at a remarkably high critical temperature Tc=40K…
We have studied the magneto-optical and magnetotrasnport properties of GaMnAs thin films with high Mn concentrations (x= 12.2 - 21.3%) grown by molecular-beam epitaxy. These heavily Mn-doped GaMnAs films were formed by decreasing the growth…
In dilute astrophysical plasmas, thermal conduction is primarily along magnetic field lines, and therefore highly anisotropic. As a result, the usual convective stability criterion is modified from a condition on entropy to a condition on…
We report the observation of a weak spontaneous magnetic field appearing at the transition temperature of $\rm YBa_2Cu_3O_{7-\delta}$ into the superconducting state. The effect is observed in 14 out of 15 epitaxial films grown on different…
Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong…
We report scanning tunneling spectroscopy imaging of the vortex lattice in single crystalline MgB2. By tunneling parallel to the c-axis, a single superconducting gap (Delta = 2.2 meV) associated with the pi-band is observed. The vortices in…
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…
Symmetry-lowering structural phase transitions result in multiple degenerate structures whose coexistence is determined by macroscopic strain compatibility. In quantum materials, these structural transformations often couple to electronic…
Dynamic ordering of driven vortex matter has been investigated in the peak effect regime of both amorphous MoGe films and 2H-NbSe2 crystals by mode locking (ML) and dc transport measurements. ML features allow us to trace how the shear…
We report measurements of the magnetic penetration depth \lambda_m(T) in the presence of a DC magnetic field in optimally doped BSCCO-2212 single crystals. Warming, after magnetic field is applied to a zero-field cooled sample, results in a…
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 infrared (900-1100 cm-1) Faraday rotation and circular dichroism are measured in the normal state of underdoped High Tc superconductors and used to study the magneto-transport. YBa2Cu3O6+x thin films are investigated in the temperature…
A hybrid system which consists of a superconducting (SC) Pb film (100 nm thickness) containing $\sim$1 vol% single domain ferromagnetic (FM) Co particles of mean-size $\sim$4.5 nm reveal unusual magnetic properties: (i) a controlled…
We investigated vortex dynamics in a single-crystal sample of type-II superconductor NbSe$_{2}$ using scanning tunneling microscopy at 4.2 K. The decay of the magnetic field at a few nT/s in our superconducting magnet induced the…
Magnetotransport measurements are presented on polycrystalline MgB2 samples. The resistive upper critical magnetic field reveals a temperature dependence with a positive curvature from Tc = 39.3 K down to about 20 K, then changes to a…
2D ferromagnets offer valuable insights into the fundamentals of magnetism and stimulate the progress of ultracompact spintronics. The demand for seamless integration of the materials with the Si technology, particularly helpful to their…
The Ginzburg-Landau functional for a two-gap superconductor is derived within the weak-coupling BCS model. The two-gap Ginzburg-Landau theory is, then, applied to investigate various magnetic properties of MgB2 including an upturn…
We address a recent experiment in which a strong decrease of the resistance of a superconducting film has been observed when a remote unbiased gate was placed above the film. Here we explain the experimental finding as a suppression of the…
High quality, ultrathin, superconducting films are required for advanced devices such as hot-electron bolometers, superconducting nanowire single photon detectors, and quantum applications. Using Hybrid Physical-Chemical Vapor Deposition…