Deterministic field-free skyrmion nucleation at a nano-engineered injector device.

Magnetic skyrmions are topological solitons promising for applications as encoders for digital information. A number of different skyrmion-based memory devices have been recently proposed. In order to demonstrate a viable skyrmion-based memory device, it is necessary to reliably and reproducibly nucleate, displace, detect, and delete the magnetic skyrmions, possibly in absence of external applied magnetic fields, which would needlessly complicate the device design. While the skyrmion displacement and detection have both been thoroughly investigated, much less attention has been dedicated to the study of the skyrmion nucleation process and its sub-ns dynamics. In this study, we investigate the nucleation of magnetic skyrmions from a dedicated nano-engineered injector, demonstrating the reliable magnetic skyrmion nucleation at the remnant state. The sub-ns dynamics of the skyrmion nucleation process were also investigated, allowing us to shine light on the physical processes driving the nucleation.

[1]  W. Hager,et al.  and s , 2019, Shallow Water Hydraulics.

[2]  S. Auffret,et al.  Ultrafast magnetization switching by spin-orbit torques , 2013, 1310.5586.

[3]  A. Fert,et al.  Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmions at room temperature. , 2016, Nature nanotechnology.

[4]  A. Locatelli,et al.  Room-temperature chiral magnetic skyrmions in ultrathin magnetic nanostructures. , 2016, Nature nanotechnology.

[5]  Yan Zhou,et al.  Deterministic creation and deletion of a single magnetic skyrmion observed by direct time-resolved X-ray microscopy , 2017, 1706.06726.

[6]  Gerhard Jakob,et al.  Thermal skyrmion diffusion used in a reshuffler device , 2018, Nature Nanotechnology.

[7]  Danna Zhou,et al.  d. , 1840, Microbial pathogenesis.

[8]  C. Pfleiderer,et al.  Emergent electrodynamics of skyrmions in a chiral magnet , 2012, Nature Physics.

[9]  Thomas de Quincey.  [C] , 2000, The Works of Thomas De Quincey, Vol. 1: Writings, 1799–1820.

[10]  L. Buda-Prejbeanu,et al.  Fast current-induced domain-wall motion controlled by the Rashba effect. , 2011, Nature materials.

[11]  I. Dzyaloshinsky.  A thermodynamic theory of “weak” ferromagnetism of antiferromagnetics , 1958 .

[12]  Yan Zhou,et al.  Current-driven dynamics and inhibition of the skyrmion Hall effect of ferrimagnetic skyrmions in GdFeCo films , 2017, Nature Communications.

[13]  E. Linfield,et al.  Discrete Hall resistivity contribution from Néel skyrmions in multilayer nanodiscs , 2017, Nature Nanotechnology.

[14]  J. Sinova,et al.  Skyrmion production on demand by homogeneous DC currents , 2016, 1610.08313.

[15]  T. Tyliszczak,et al.  PolLux: a new facility for soft x-ray spectromicroscopy at the Swiss Light Source. , 2008, The Review of scientific instruments.

[16]  Wagner,et al.  Absorption of circularly polarized x rays in iron. , 1987, Physical review letters.

[17]  Kang L. Wang,et al.  Blowing magnetic skyrmion bubbles , 2015, Science.

[18]  C. Marrows,et al.  Dynamic Imaging of the Delay- and Tilt-Free Motion of Néel Domain Walls in Perpendicularly Magnetized Superlattices. , 2018, Nano letters.

[19]  H. Ohno,et al.  Scalability and wide temperature range operation of spin-orbit torque switching devices using Co/Pt multilayer nanowires , 2018, Applied Physics Letters.

[20]  C. Marrows,et al.  Pinning and hysteresis in the field dependent diameter evolution of skyrmions in Pt/Co/Ir superlattice stacks , 2017, Scientific Reports.

[21]  Kang L. Wang,et al.  Direct observation of the skyrmion Hall effect , 2016, Nature Physics.

[22]  F. Buttner,et al.  Skyrmion Hall effect revealed by direct time-resolved X-ray microscopy , 2016, Nature Physics.

[23]  T. Moriya.  Anisotropic Superexchange Interaction and Weak Ferromagnetism , 1960 .

[24]  C. Marrows,et al.  Measuring and tailoring the Dzyaloshinskii-Moriya interaction in perpendicularly magnetized thin films , 2014 .

[25]  Kang L. Wang,et al.  Low-power non-volatile spintronic memory: STT-RAM and beyond , 2013 .

[26]  S. Eisebitt,et al.  Field-free deterministic ultrafast creation of magnetic skyrmions by spin-orbit torques. , 2017, Nature nanotechnology.

[27]  J. Raabe,et al.  Sub-100ps Magnetic Imaging at the PolLux Endstation of the Swiss Light Source , 2018, Microscopy and Microanalysis.

[28]  Benjamin Krueger,et al.  Observation of room-temperature magnetic skyrmions and their current-driven dynamics in ultrathin metallic ferromagnets. , 2015, Nature materials.

[29]  R. Wiesendanger,et al.  Pinning and movement of individual nanoscale magnetic skyrmions via defects , 2016, 1601.05204.

[30]  F. García-Sánchez,et al.  The design and verification of MuMax3 , 2014, 1406.7635.

[31]  A. Stashkevich,et al.  Current-induced skyrmion generation and dynamics in symmetric bilayers , 2016, Nature Communications.

[32]  Michael D. Schneider,et al.  Dynamics and inertia of skyrmionic spin structures , 2015, Nature Physics.

[33]  Jörg Raabe,et al.  Spatially and time-resolved magnetization dynamics driven by spin-orbit torques. , 2017, Nature nanotechnology.

[34]  M. Stier,et al.  Skyrmion-Anti-Skyrmion Pair Creation by in-Plane Currents. , 2017, Physical Review Letters.

[35]  S. Parkin,et al.  Chiral spin torque at magnetic domain walls. , 2013, Nature nanotechnology.

[36]  G. Sawatzky,et al.  Journal of Physics and Chemistry of Solids 40th Anniversary - Preface , 1998 .

[37]  P. Alam.  ‘S’ , 2021, Composites Engineering: An A–Z Guide.

[38]  A. Fert,et al.  Skyrmions on the track. , 2013, Nature nanotechnology.

[39]  Y. Tokura,et al.  Topological properties and dynamics of magnetic skyrmions. , 2013, Nature nanotechnology.

[40]  B. Kalantari,et al.  Photon Counting System for Time-resolved Experiments in Multibunch Mode , 2010 .

[41]  T. Tyliszczak,et al.  Correlation between spin structure oscillations and domain wall velocities , 2013, Nature Communications.

[42]  Yan Zhou,et al.  Magnetic skyrmion logic gates: conversion, duplication and merging of skyrmions , 2014, Scientific Reports.