On the three-dimensional structure of magnetic skyrmions
Physical Review B American Physical Society 106 (2022) 214404
Abstract:
Magnetic skyrmions (skyrmions hereafter) are magnetization configurations, whose topological robustness and nano-scale size have led to speculation that they could find use as a next-generation information carrier. Skyrmions have been observed in magnetic multilayer materials that are thin compared to the radius of a skyrmion, and chiral cubic single crystals that can be far larger than any characteristic skyrmion scale. In these single crystals, one would expect that skyrmions could exhibit interesting 3D characteristics. Here, the symmetry of the micromagnetic free energy is investigated. This symmetry permits a complex 3D modulation of a skyrmion string, which we show to be a requirement of a skyrmion coexisting with the conical state. We discuss the implications of this modulation with respect to Thiele’s equation and inter-skyrmion interactions. Further to this internal modulation, we study theoretically and show experimentally that the strings themselves must contort towards the surfaces of their confining crystals.Time-resolved measurement of spin excitations in Cu2OSeO3
Physical Review B: Condensed Matter and Materials Physics American Physical Society 106 (2022) 174409
Abstract:
Magnetic diffraction in combination with x-ray detected ferromagnetic resonance (DFMR) is a powerful technique for performing time-resolved measurements on individual spin textures. Here, we study the ferromagnetic resonance (FMR) modes of both the conical and field-polarized phases in the chiral magnet Cu2OSeO3. Following the identification of the FMR modes at different temperatures using broadband vector network analyzer FMR, we use DFMR on the crystalline (001) Bragg peak to reveal the time-dependent spin configurations of the selected FMR modes. By being able to measure both the amplitude and phase response of the spin system across the resonance, a continuous phase advance (of 180◦) in the conical mode, and a phase lag (of 180◦) in the field-polarized mode is found. By performing dynamic measurements in the conical phase as a function of the linear polarization angle of the x-rays, i.e., successively probing the dynamics of the moments, we find an inversion of the dynamics along the conical axis upon inverting the applied field direction. By allowing for time-resolved measurements of the phase and amplitude of individual magnetic phases, DFMR opens up new opportunities for obtaining a deeper understanding of the complex dynamics of chiral magnets.Time-resolved measurement of spin excitations in
Cu 2 OSeO 3
Physical Review B American Physical Society (APS) 106:17 (2022) 174409
Time-resolved measurement of spin excitations in Cu$_2$OSeO$_3$
(2022)
Ultrahigh carrier mobility in Cd3As2 nanowires
physica status solidi (RRL) - Rapid Research Letters Wiley 17:2 (2022) 2200365