We present local tunneling spectroscopy experiments in the superconducting and ferromagnetic phases of the reentrant superconductor ErRh4B4. The tunneling conductance curves jump from showing normal to superconducting features within a few mK close to the ferromagnetic transition temperature, with a clear hysteretic behavior. Within the ferromagnetic phase, we do not detect any superconducting ...

We report collective ferromagnetic behavior with high Curie temperatures (T(c)) in Fe dot assemblies supported by the Cu(111) surface. Our ability to tune the average size and spacing of the individual dots allows us to conclude that enhanced magnetic anisotropy cannot account for this high-T(c) ferromagnetic order. Because our Monte Carlo simulations have ruled out the dipolar interaction as t...

Developing optically transparent magnets at room temperature is an important challenge. They would bring many innovations to various industries, not only for electronic and magnetic devices but also for optical applications. Here we introduce FeCo-(Al-fluoride) nanogranular films exhibiting ferromagnetic properties with high optical transparency in the visible light region. These films have a n...

The potential of nanosphere lithography utilizing di-block copolymers is demonstrated. The starting configuration is a single layer of micelles, filled with silica, deposited on a ferromagnetic system. After removing the organic shell the SiO2 cores remain on the surface and are used as shadow mask for a succeeding ion milling process. It is demonstrated how the magnetic properties of the dots ...

Graphene on an insulating ferromagnetic substrate—ferromagnetic insulator or ferromagnetic metal with a tunnel barrier—is expected to exhibit large exchange and spin-orbit couplings due to proximity effects. We use a realistic transport model of charge-disorder scattering and solve the linearized Boltzmann equation numerically exactly for the anisotropic Fermi contours of modified Dirac electro...

In this article we apply a recently invented analytical real-space renormalization group formulation which is based on numerical concepts of the density matrix renormalization group. Within a rigorous mathematical framework we construct non-perturbative renormalization group transformations for the spin1 2 XXX Heisenberg model in the finite temperature regime. The developed renormalization grou...

We propose an Ising machine made of microelectromechanical systems (MEMS), where the annealing process is automatically executed by a dissipation mechanism. The core structure series buckled plates. Two stable positions each plate (left and right) represent its binary state acting as bit so that works mechanical memory. electrostatic interaction between adjacent plates introduced applying volta...