Pavel Baláž

Tunable short-wavelength spin wave excitation from pinned magnetic domain walls

Miniaturization of magnonic devices for wave-like computing requires emission of short-wavelength spin waves, a key feature that cannot be achieved with microwave antennas. In this paper, we propose a tunable source of short-wavelength spin waves based on highly localized and strongly pinned magnetic domain walls in ferroelectric-ferromagnetic bilayers. When driven into oscillation by a microwave spin-polarized current, the magnetic domain walls emit spin waves with the same frequency as the excitation current. The amplitude of the emitted spin waves and the range of attainable excitation frequencies depend on the availability of domain wall resonance modes. In this respect, pinned domain walls in magnetic nanowires are particularly attractive. In this geometry, spin wave confinement perpendicular to the nanowire axis produces a multitude of domain wall resonances enabling efficient spin wave emission at frequencies up to 100 GHz and wavelengths down to 20 nm. At high frequency, the emission of spin waves in magnetic nanowires becomes monochromatic. Moreover, pinning of magnetic domain wall oscillators onto the same ferroelectric domain boundary in parallel nanowires guarantees good coherency between spin wave sources, which opens perspectives towards the realization of Mach-Zehnder type logic devices and sensors.

Current-induced dynamics of composite free layer with antiferromagnetic interlayer exchange coupling

Current-induced dynamics in spin valves including composite free layer with antiferromagnetic interlayer exchange coupling is studied theoretically within the diffusive transport regime. We show that current-induced dynamics of a synthetic antiferromagnet is significantly different from dynamics of a synthetic ferrimagnet. From macrospin simulations we obtain conditions for switching the composite free layer, as well as for appearance of various self-sustained dynamical modes. Numerical simulations are compared with simple analytical models of critical current based on linearized Landau-Lifshitz-Gilbert equation.

Electronic and transport properties of the Mn-doped topological insulator Bi

We present a first-principles study of the electronic, magnetic, and transport properties of the topological insulator Bi

_{2}

_{2}

Te

Te

_{3}

_{3}

: A first-principles study

doped with Mn atoms in substitutional (Mn

Transverse spin penetration length in metallic spin valves

_{\rm Bi}

Static properties and current-induced dynamics of pinned 90∘ magnetic domain walls under applied fields: An analytic approach

) and interstitial van der Waals gap positions (Mn

Physical properties of the tetragonal CuMnAs: A first-principles study

_{\rm i}