arXiv subjects

C. Moutafis

Publications and source records attributed to C. Moutafis.

3 recordsLinked to original sources

arXiv2024

Materials for Quantum Technologies: a Roadmap for Spin and Topology

In this Perspective article, we explore some of the promising spin and topology material platforms (e.g. spins in semi- and superconductors, skyrmionic, topological and 2D materials) being developed for such quantum components as qubits, superconducting memories, sensing, and metrological standards and discuss their figures of merit. Spin- and topology-related quantum phenomena have several advantages, including high coherence time, topological protection and stability, low error rate, relative ease of engineering and control, simple initiation and read-out. However, the relevant technologies are at different stages of research and development, and here we discuss their state-of-the-art, potential applications, challenges and solutions.

cond-mat.mes-hall↗

arXiv2018

Controlled anisotropic dynamics of tightly bound skyrmions in a synthetic ferrimagnet due to skyrmion-deformation mediated by induced uniaxial in-plane anisotropy

We study speed and skew deflection-angle dependence on skyrmion deformations of a tightly bound two-skyrmion state in a synthetic ferrimagnet. We condsider here, an in-plane uniaxial magnetocrystalline anisotropy-term in order to induce lateral shape distortions and an overall size modulation of the skyrmions due to a reduction of the effective out-of-plane anisotropy, thus affecting the skyrmion speed, skew-deflection and inducing anisotropy in these quantities with respect to the driving current-angle. Because of frustrated dipolar interactions in a synthetic ferrimagnet, sizeable skyrmion deformations can be induced with relatively small induced anisotropy constants and thus a wide range of tuneability can be achieved. We also show analytically, that a consequence of the skyrmion deformation can, under certain conditions cause a skyrmion deflection with respect to driving-current angles, unrelated to the topological charge. Results are analyzed by a combination of micromagnetic simulations and a compound particle description within the Thiele-formalism from which an over-all mobility tensor is constructed. This work offers an additional path towards in-situ tuning of skyrmion dynamics.

cond-mat.mes-hall↗

arXiv2015

Skyrmions at room temperature : From magnetic thin films to magnetic multilayers

Facing the ever-growing demand for data storage will most probably require a new paradigm. Magnetic skyrmions are anticipated to solve this issue as they are arguably the smallest spin textures in magnetic thin films in nature. We designed cobalt-based multilayered thin films where the cobalt layer is sandwiched between two heavy metals providing additive interfacial Dzyaloshinskii-Moriya interactions, which reach about 2 mJ/m2 in the case of the Ir/Co/Pt multilayers. Using a magnetization-sensitive scanning x-ray transmission microscopy technique, we imaged magnetic bubble-like domains in these multilayers. The study of their behavir in magnetic field allows us to conclude that they are actually magnetic skyrmions stabilized by the Dzyaloshinsskii-Moriya interaction. This discoevry of stable skyrmions at room temperature in a technologically relevant material opens the way for device applications in a near future.

cond-mat.mtrl-sci↗