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11.11.2021: Nature publication

A paper on “Readout of an antiferromagnetic spintronics system by strong exchange coupling of Mn2Au and Permalloy” resulting from a collaboration between different teams from the Johannes Gutenberg-University Mainz and Twist Group Leader Karin Everschor-Sitte affiliated with the University of Duisburg-Essen, has been published in Nature Communications. In this paper, they demonstrate strong exchange coupling of the metallic antiferromagnet Mn2Au that exhibits Néel spin-orbit torques with thin ferromagnetic Permalloy layers and show one-to-one imprinting of the antiferromagnetic on the ferromagnetic domain pattern. This allows to benefit from the well-established read-out methods of ferromagnets, while the essential advantages of antiferromagnetic spintronics like ultra-fast dynamics and stability are only slightly diminished. Detailed information: Readout of an antiferromagnetic spintronics system by strong exchange coupling of Mn2Au and Permalloy S. P. Bommanaboyena, D. Backes, L. S. I. Veiga, S. S. Dhesi, Y. R. Niu, B. Sarpi, T. Denneulin, A. Kovács, T. Mashoff, O. Gomonay, ...

A paper on “Scalable computational measures for entropic detection of latent relations and their applications to magnetic imaging” resulting from a collaboration between Illia Horenko from University of Lugano in Switzerland, Terence O’Kane from University of Tasmania, the postdoctoral researcher Davi Rodrigues and Twist Group Leader Karin Everschor-Sitte both affiliated with the University of Duisburg-Essen, has been published in Communications in Applied Mathematics and Computational Science. In this paper, they introduce two novel computationally-scalable data relation measures the latent dimension and the latent entropy taking into account latent temporal relations between processes of interest and analyse their mathematical and computational properties. They have the potential to assist current efforts to enhance the resolution of experimental techniques by providing key insights into the noisy observed data when common data measures fail. These results are highly relevant to detect subtle material inhomogeneity patterns in magnetic imaging. For example these data-driven tools can ...

Congratulations to Jake Love winning the Best Picture Award 2021 of the DFG Priority Program SPP2137! Besides Jonathan Leliaert, George Bourianoff and Karin Everschor-Sitte, Jake Love from the TWIST team, affiliated with the University of Duisburg-Essen won the Best Picture Award 2021 at the Skyrmionics Picture Competition of the DFG Priority Program SPP2137 Skyrmionics – Topological Spin Phenomena in Real-Space for Applications. The awarded figure depicts a gradual overlay of the non-linearity (red) and memory capacity (blue) of a magnetic skyrmion reservoir computer. ...

A paper on “Spin-Wave Driven Bidirectional Domain Wall Motion in Kagome Antiferromagnets” resulting from a collaboration between K. M. D. Hals, A. Salimath both from University of Agder in Norway and the postdoctoral researcher D. R. Rodrigues and Twist Group Leader Karin Everschor-Sitte affiliated with the Johannes Gutenberg-University Mainz and the University of Duisburg-Essen, has been published in Physical Review Letters 127, 157203 (2021). In this paper, they predict a mechanism to controllably manipulate domain walls in kagome antiferromagnets via a single linearly polarized spin-wave source. They showed that the speed and direction of the domain wall motion can be regulated by tuning the frequency of the applied spin wave. These results are highly relevant for applications in the field of antiferromagnetic insulator devices. The article is featured on the front cover of the Physical Review Letters Journal (Volume 127, Issue 15, 08 October 2021). Detailed information: Spin-Wave Driven Bidirectional Domain Wall Motion ...

Congratulations to Ross Knapman winnning the 3rd poster prize at IOPmaterials! Besides the first prize to Marcos Guimaraes from the University of Groningen and the second prize to Yang Sun from Columbia University, Ross Knapman from the TWIST team, affiliated with the Johannes Gutenberg-University Mainz and the University of Duisburg-Essen won the third prize of the IOPmaterials poster competition EmergingLeaders. For further information, visit https://twitter.com/IOPmaterials/status/1440994393327116288. ...

A book chapter on “Current-Induced Dynamics of Chiral Magnetic Structures: Creation, Motion, and Applications” resulting from a collaboration between Jan Masell from RIKEN Center for Emergent Matter Science in Japan and Twist Group Leader Karin Everschor-Sitte, has been published in a book about Chirality, Magnetism and Magnetoelectricity. In this work, they review how spin-transfer and spin-orbit-torques can be exploited to create and move chiral magnetic textures in magnets with broken inversion symmetries, including domain walls and skyrmions using electric currents. Detailed information: Current-Induced Dynamics of Chiral Magnetic Structures: Creation, Motion, and Applications Jan Masell and Karin Everschor-Sitte Book Chapter in Chirality, Magnetism and Magnetoelectricity. Topics in Applied Physics, Vol. 138, Springer (2021) ...

A paper on “Current-induced H-shaped-skyrmion creation and their dynamics in the helical phase” resulting from a collaboration between Jan Masell from RIKEN Center for Emergent Matter Science in Japan, PhD Candidate Ross Knapman, postdoctoral researcher Davi Rodrigues and Twist Group Leader Karin Everschor-Sitte affiliated with the Johannes Gutenberg-University Mainz and the University of Duisburg-Essen, has been published in Journal of Physics D. In this paper, they propose a protocol to create topological magnetic structures in helical magnets, which confine the motion of skyrmions along one-dimensional channels formed by helices to allow high-speed skyrmion motion. They furthermore analyse the stability and current-driven motion of the skyrmions in a helical background with in-plane uniaxial anisotropy fixing the orientation of the helices. These results are highly relevant for skyrmion racetrack-like applications. Detailed information: Current-induced H-shaped-skyrmion creation and their dynamics in the helical phase Ross Knapman, Davi R. Rodrigues, Jan Masell and Karin Everschor-Sitte ...

A paper on “Nonlinear Dynamics of Topological Ferromagnetic Textures for Frequency Multiplication” resulting from a collaboration between Morteza Mohseni and Philipp Pirro both from TU Kaiserslautern and postdoctoral researcher Davi R. Rodrigues, PhD Candidate Jonas Nothhelfer, PhD Candidate Ross Knapman and Twist Group Leader Karin Everschor-Sitte affiliated with the Johannes Gutenberg-University Mainz and the University of Duisburg-Essen, has been published in Physical Review Applied. In this paper, they propose that the nonlinear radio-frequency dynamics and nanoscale size of topological magnetic structures associated with their well-defined internal modes advocate their use as in materio scalable frequency multipliers for spintronic systems. They explore the excitation of eigenmodes of of isolated ferromagnetic skyrmions by fractions of the corresponding eigenfrequencies. Detailed information: Nonlinear Dynamics of Topological Ferromagnetic Textures for Frequency Multiplication Davi R. Rodrigues, Jonas Nothhelfer, Morteza Mohseni, Ross Knapman, Philipp Pirro and Karin Everschor-Sitte Physical Review Applied 16, 014020 (2021) ...

Karin_Everschor-Sitte

Karin Everschor-Sitte has accepted a call for a professorship in Theoretical Physics at the University of Duisburg-Essen. The press release of April 2021 can be found at https://www.uni-due.de/2021-04-28-nanomagnetismus-everschor-sitte. ...

A paper on “A deeper look into natural sciences with physics-based and data-driven measures” resulting from a collaboration between Illia Horenko from University of Lugano in Switzerland, Susanne Gerber from Medical Center of the Johannes Gutenberg University Mainz, postdoctoral researcher Davi R. Rodrigues and Twist Group Leader Karin Everschor-Sitte both affiliated with the Johannes Gutenberg-University Mainz, has been published in iScience. In this paper, they discuss two state-of-the-art machine learning data-driven tools latent entropy and latent dimension to analyse latent effects in data to glean much more information from an experimental data set to study matter. They explain the applicability of those techniques in natural science to reveal so far unobserved features on several examples like a gradient in a magnetic measurement or a latent network of glymphatic channels from the mouse brain microscopy data. Detailed information: A deeper look into natural sciences with physics-based and data-driven measures Davi R. ...