Fundamental solution of the time-space bi-fractional diffusion equation with a kinetic source term for anomalous transport.

The purpose of this paper is to study the fundamental solution of the time-space bi-fractional diffusion equation incorporating an additional kinetic source term in semi-infinite space. The equation is a generalization of the integer-order model (also known as the Debye-Falkenhagen equation) by replacing the first-order time derivative with the Caputo fractional derivative of order , and the second-order space derivative with the Riesz-Feller fractional derivative of order . Using the Laplace-Fourier transforms method, it is shown that the parametric solutions are expressed in terms of the Fox's H-function that we evaluate for different values of and .

XMCD and study of interface-engineered ultrathin Ru/Co/W/Ru films with perpendicular magnetic anisotropy and strong Dzyaloshinskii-Moriya interaction.

Understanding the nature of recently discovered spin-orbital induced phenomena and a definition of a general approach for "ferromagnet/heavy-metal" layered systems to enhance and manipulate spin-orbit coupling, spin-orbit torque, and the Dzyaloshinskii-Moriya interaction (DMI) assisted by atomic-scale interface engineering are essential for developing spintronics and spin-orbitronics. Here, we exploit X-ray magnetic circular dichroism (XMCD) spectroscopy at the -edges of 5d and 4d non-magnetic heavy metals (W and Ru, respectively) in ultrathin Ru/Co/W/Ru films to determine their induced magnetic moments due to the proximity to the ferromagnetic layer of Co. The deduced orbital and spin magnetic moments agree well with the theoretically predicted values, highlighting the drastic effect of constituting layers on the system's magnetic properties and the strong interfacial DMI in Ru/Co/W/Ru films.

On the origin of the electron accumulation layer at clean InAs(111) surfaces.

In this paper, we provide a comprehensive theoretical analysis of the electronic structure of InAs(111) surfaces with special attention paid to the energy region close to the fundamental bandgap. Starting from the bulk electronic structure of InAs calculated using the PBE functional with the inclusion of Hubbard correction and spin-orbit coupling, we derive proper values for the bandgap, split-off energy, as well as effective electron, light-hole and heavy-hole masses in full consistent with the available experimental results. Besides that we address the projected density of states associated with p orbitals of bulk indium and arsenic atoms.

Localized surface electromagnetic waves in CrI-based magnetophotonic structures.

Resulting from strong magnetic anisotropy two-dimensional ferromagnetism was recently shown to be stabilized in chromium triiodide, CrI, in the monolayer limit. While its properties remain largely unexplored, it provides a unique material-specific platform to unveil its electromagnetic properties associated with coupling of modes. Indeed, trigonal symmetry in the presence of out-of-plane magnetization results in a non-trivial structure of the conductivity tensor, including the off-diagonal terms.

Oxygen vacancy in ZnO-phase: pseudohybrid Hubbard density functional study.

The study of zinc oxide, within the homogeneous electron gas approximation, results in overhybridization of zinc 3d shell with oxygen 2p shell, a problem shown for most transition metal chalcogenides. This problem can be partially overcome by using LDA +(or, GGA +) methodology. However, in contrast to the zinc 3d orbital, Hubbard type correction is typically excluded for the oxygen 2p orbital.

Another view on Gilbert damping in two-dimensional ferromagnets.

A keen interest towards technological implications of spin-orbit driven magnetization dynamics requests a proper theoretical description, especially in the context of a microscopic framework, to be developed. Indeed, magnetization dynamics is so far approached within Landau-Lifshitz-Gilbert equation which characterizes torques on magnetization on purely phenomenological grounds. Particularly, spin-orbit coupling does not respect spin conservation, leading thus to angular momentum transfer to lattice and damping as a result.