Imaging the stochastic microstructure and dynamic development of correlations in perpendicular artificial spin ice

Authors

Susan Kempinger, Department of Physics, The Pennsylvania State University, University Park, PA
Robert D. Fraleigh, Communications, Information and Navigation Office, Applied Research Laboratory, The Pennsylvania State University, University Park, PA
Paul E. Lammert, Department of Physics, The Pennsylvania State University, University Park, PA
Sheng Zhang Zhang, CUNY Advanced Science Research CenterFollow
Vincent H. Crespi, Department of Physics, The Pennsylvania State University, University Park, PA
Peter Schiffer, Department of Applied Physics and Department of Physics, Yale University, New Haven, CT
Nitin Samarth, Department of Physics, The Pennsylvania State University, University Park, PAFollow

Document Type

Article

Publication Date

1-2-2020

Abstract

We use spatially resolved magneto-optical Kerr microscopy to track the complete microstates of arrays of perpendicular anisotropy nanomagnets during magnetization hysteresis cycles. These measurements, along with our statistical methodology, allow us to disentangle the intertwined effects of nearest-neighbor interactions, disorder, and stochasticity on magnetization switching. We find that the nearest-neighbor correlations depend on both interaction strength and disorder. We also find that although the global characteristics of the hysteretic switching are repeatable, the exact microstate sampled is stochastic with the behavior of individual islands varying between nominally identical runs. These protocols provide another way of understanding the relationship between macrohistory and microhistory in artificial magnetic arrays.

Comments

This article was originally published in Physical Review Research, available at https://doi.org/10.1103/PhysRevResearch.2.012001

This work is distributed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).