Abstract
Finite temperature micromagnetic simulations are used to probe stochastic domain wall pinning behaviours in magnetic nanowire devices. By exploring field-induced propagation both below and above the Walker breakdown field it is shown that all experimentally observed phenomena can be comprehensively explained by the influence of thermal perturbations on the domain walls’ magnetisation dynamics. Nanowires with finite edge roughness are also investigated, and these demonstrate how this additional form of disorder couples with thermal perturbations to significantly enhance stochasticity. Cumulatively, these results indicate that stochastic pinning is an intrinsic feature of DW behaviour at finite temperatures, and would not be suppressed even in hypothetical systems where initial DW states and experimental parameters were perfectly defined.
Highlights
Understanding and controlling stochastic effects in nanomagnetic systems is an area of major research interest due to the critical importance of these effects to the performance of data storage technologies
Our work indicates that stochasticity is an intrinsic feature of domain walls (DWs) motion at finite temperatures, and would not be suppressed even in hypothetical systems where initial DW states and experimental parameters were perfectly defined
We note that our simulations reproduce all of the major features of stochastic DW behaviour observed experimentally: Our results show stochastic pinning behaviour to be supressed at very low propagation fields, below Walker breakdown (WB)
Summary
Understanding and controlling stochastic effects in nanomagnetic systems is an area of major research interest due to the critical importance of these effects to the performance of data storage technologies. For more complex mesoscopic systems that exhibit larger numbers of stable states and multiple transitional paths, effective modelling becomes much more difficult. In this regime, magnetisation states and switching behaviour are best modelled using micromagnetic simulations. Logic[6,7] and memory[8] devices based on their pinning and propagation have great technological potential, but development has been inhibited, in part by problems of stochasticity. Experimental observations of these effects can be classified into three broad categories:. (2) DWs pinned at artificial defect sites have complex, multi-mode depinning field distributions11–15. (3) DWs pass probabilistically through defect sites even when under the influence of applied fields that would not be expected to be able to induce depinning[13,16,17]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
