Related papers: Magnetoresistance and localization in bosonic insu…
Localization and dephasing of conduction electrons in a low carrier density ferromagnet due to scattering on magnetic fluctuations is considered. We claim the existence of the "mobility edge", which separates the states with fast diffusion…
This paper considers certain materials, including topological insulators, where spin rotation symmetry is broken much more strongly than time reversal symmetry. When these materials are in the diffusive regime, i.e. when they have disorder…
Owing to the unique features of low Gilbert damping, long spin-diffusion lengths and zero Ohmic losses, magnetic insulators are promising candidate materials for next-generation spintronic applications. However, due to the localized…
We calculate the semiclassical magnetoresistivity $\rho_{xx}(B)$ of non-interacting fermions in two dimensions moving in a weak and smoothly varying random potential or random magnetic field. We demonstrate that in a broad range of magnetic…
In the absence of parity and time-reversal symmetries, insulators can exhibit magnetoelectric responses, in which applied magnetic fields induce charge polarization and, conversely, applied electric fields induce magnetization. While there…
Magnetization reversal in permanent magnets occurs by the nucleation and expansion of reversed domains. Micromagnetic theory offers the possibility to localize the spots within the complex structure of the magnet where magnetization…
In hopping magnetoresistance of doped insulators, an applied magnetic field shrinks the electron (hole) s-wave function of a donor or an acceptor and this reduces the overlap between hopping sites resulting in the positive magnetoresistance…
We study the variable-range hopping (VRH) of bosons in an array of sites with short-range interactions and a large characteristic coordination number. The latter leads to strong quantum interference phenomena yet allows for their analytical…
We study bosonic atoms in small optical lattices by exact diagonalization and observe a striking similarity to the superfluid to Mott insulator transition in macroscopic systems. The momentum distribution, the formation of an energy gap,…
We show by means of an exact numerical approach that the momentum distribution of a free expanding gas of hard-core bosons on a one-dimensional lattice approaches to the one of noninteracting fermions, acquiring a Fermi edge. Yet there is a…
Ferromagnetic polarons are self trapped states of an electron in a locally spin polarised environment. They occur close to the magnetic $T_c$ in low carrier density local moment magnets when the electron-spin coupling is comparable to the…
We discuss an experiment in which two magnetic insulators that both show a field-induced magnetic-ordering transition are weakly coupled to one another and are placed into an ex- ternal magnetic field. If the respective magnetic states can…
We are all familiar with ferromagnetic and antiferromagnetic materials, in which the localized ionic moments (in case of ionic insulators) or the electronic spins (in case of metals) go into a long-range ordered state with a net macroscopic…
Theory of interference-induced quantum corrections to conductivity is developed for two dimensional systems with chiral spin textures including skyrmions. The effect of exchange interaction between electrons and spin textures on weak…
In superlattices of twisted semiconductor monolayers, tunable moir\'e potentials emerge, trapping excitons into periodic arrays. In particular, spatially separated interlayer excitons are subject to a deep potential landscape and they…
We have investigated the local magneto-transport in high-quality 2D electron systems at low carrier densities. The positive magneto-resistance in perpendicular magnetic field in the strongly insulating regime has been measured to evaluate…
We investigate the field-induced insulator-to-superfluid transition of bosonic quasiparticles in $S=1/2$ weakly-coupled dimer antiferromagnets. In presence of realistic disorder due to site dilution of the magnetic lattice, we show that the…
Recent experiments on ultracold atomic gases in an optical lattice potential have produced a Mott insulating state of Rb atoms. This state is stable to a small applied potential gradient (an `electric' field), but a resonant response was…
We have performed magnetoresistance measurements on polyfluorene sandwich devices in weak magnetic fields as a function of applied voltage, device temperature (10K to 300K), film thickness and electrode materials. We observed either…
Strong spin-orbit coupling in topological insulators results in the ubiquitously observed weak antilocalization feature in their magnetoresistance. Here we present magnetoresistance measurements in ultra thin films of the topological…