We have performed a comparison of magnetoresistance and structure of epitaxial and textured Fe/Cr superlattices grown by molecular-beam epitaxy ~MBE! and magnetron sputtering with either ~110! and ~100! orientations on a variety of substrates. MBE samples grown along the ~100! orientation, exhibit narrower rocking curves ~mosaic spread! and lower saturation resistivities than sputtered samples....

Low-field magnetoresistance is ubiquitous in low-dimensional metallic systems with high resistivity and well understood as arising due to quantum interference on self-intersecting diffusive trajectories. We have found that in graphene this weak-localization magnetoresistance is strongly suppressed and, in some cases, completely absent. The unexpected observation is attributed to mesoscopic corr...

We perform a semiclassical calculation of the magnetoresistance of spinless two-dimensional fermions in a long-range correlated random magnetic field. In the regime relevant for the problem of the half filled Landau level the perturbative Born approximation fails and we develop a new method of solving the Boltzmann equation beyond the relaxation time approximation. In absence of interactions, e...

MgO-based magnetic tunnel junctions have been fabricated with a thin Co40Fe40B20 CoFeB layer in the pinned synthetic antiferromagnetic CoFe/Ru/CoFeB stack. An inverted tunneling magnetoresistance is observed due to the unbalanced synthetic antiferromagnet. Superparamagnetic nanoparticles form when the CoFeB layer is thinner than 1.5 nm, and an abnormal temperature dependence of the junction res...

We report on magnetoresistance oscillations in superconducting NbNx nanowires synthesized through ammonia gas annealing of NbSe3 precursor nanostructures. Though the transverse dimensions of the nanowires are much larger than the superconducting coherence length, the voltage-current characteristics of these nanowires at low temperatures are reminiscent of onedimensional superconductors where qu...

In a high mobility two-dimensional electron gas (2DEG) realized in a GaAs / Al0.3Ga0.7As quantum well we observe changes in the Shubnikov-de Haas oscillations (SdHO) and in the Hall resistance for different sample geometries. We observe for each sample geometry a strong negative magnetoresistance around zero magnetic field which consists of a peak around zero magnetic field and of a huge magnet...

The spin memristive devices combining memristance and tunneling magnetoresistance have promising applications in multibit nonvolatile data storage and artificial neuronal computing. However, it is a great challenge for simultaneous realization of large memristance and magnetoresistance in one nanoscale junction, because it is very hard to find a proper spacer layer which not only serves as good...

The interlayer magnetoresistance of the quasi-two-dimensional metal a-~BEDT-TTF!2KHg~SCN!4 is considered. In the temperature range from 0.5 to 10 K and for fields up to 10 T the magnetoresistance has a stronger temperature dependence than the zero-field resistance. Consequently Kohler’s rule is not obeyed for any range of temperatures or fields. This means that the magnetoresistance cannot be d...

Detailed studies of the magnetoresistance of α-(ET)2KHg(SCN)4 and α(ET)2TlHg(SCN)4 as a function of temperature, magnetic field strength, and field orientation are reported. Below 15 K, the temperature dependence of the magnetoresistance is metallic (dR/dT > 0) for magnetic field orientation corresponding to an angular dependent magnetoresistance oscillation (AMRO) minimum and nonmetallic (dR/d...

We report quasi-two-dimensional Dirac fermions and quantum magnetoresistance in LaAgBi2. The band structure shows several narrow bands with nearly linear energy dispersion and Diraccone-like points at the Fermi level. The quantum oscillation experiments revealed one quasi-twodimensional Fermi pocket and another complex pocket with small cyclotron resonant mass. The in-plane transverse magnetore...