Speaker
Description
Since the magnetic skyrmion is a topologically protected particle-like domain in the ferromagnetic film, it can survive under thermal agitations and shows Brownian motion. The skyrmion system can be an ideal platform to design unconventional computers like stochastic/Brownian computers. Therefore, investigation of the Brownian motion of the magnetic skyrmion is now the subject of scientific and technical interest [1,2].
In this talk, experimental proof of a non-vanishing x-velocity to y-coordinate correlation will be shown. The result is explained by the Thiele equation including a stochastic field [3,4]. Description of the phenomena introduces the gyro-diffusion constant [5] that is special for the diffusion of the chiral particles like skyrmions. The existence of the x-velocity to y-coordinate correlation also evidences the perpetual rotation motion of the skyrmion. Theory shows that the result does not conflict with the 2nd law of thermodynamics and the van Leeuwen theorem.
Acknowledgments
The authors acknowledge Mr. Y. Jibiki of Osaka University, Dr. S. Auffret, Dr. C. Baraduc, and Dr. Hélèn Béa of Spintech, France for their initial contributions. The authors also acknowledge Dr. M. Oogane and Dr. K. Saito. This research and development work was supported by the ULVAC, Inc., the Ministry of Internal Affairs and Communications, Basic research S (20H05666) of JSPS, and CREST (Non-classical Spin project) of JST.
References
[1] Y. Jibiki et al., Appl. Phys. Lett. 117, 082402 (2020).
[2] L. Zhao et al., Phys. Rev. Lett. 125, 027206 (2020).
[3] A. Thiele et al., Phys. Rev. Lett. 30, 230 (1973).
[4] C. Schuette et al., Phys. Rev. B 90, 174434 (2014)
[5] E. Tamura et al. https://arxiv.org/abs/2005.04860.
