Reconfiguration of magnetic domain structures of ErFeO3 by intense terahertz free electron laser pulses

Abstract

In this paper, we irradiated the millijoule−level THz−FEL pulses on ferromagnetic domains of ErFeO 3 single crystal. We found that magnetic domain shapes can be permanently reconfigured upon irradiation by THz-FEL, without causing permanent damage in the sample. The process could be explained by the combination of ultrafast heating−induced depinning effect and entropic force due to local thermal gradient. Our result demonstrates the potential of THz−FEL as a novel light source for the investigation of thermally induced spin dynamics in the THz region, and paves way for the THz spintronic devices in future.

Terahertz spin dynamics in rare-earth orthoferrites

“…Fig. 19 Reconfigurable magnetic domains in ErFeO 3 by static heating from a THz free-electron laser (FEL) [229] . This suggests a wider range of tuning possibility that can be afforded by this method.…”

“…Kurihara et al [229] have performed another interesting experiment, demonstrating reconfigurable magnetic domain control by laser heating. Unlike the previous examples of ultrafast transient heating, where the effect disappeared when heat diffused outside the pumped area, this work utilized static heating, a time-averaged effect of temperature rise due to laser illumination.…”

“…Reconfigurable magnetic domains in ErFeO3 by static heating from a THz free-electron laser (FEL) [229] . (a) Sequence of Faraday rotation microscopy images showing spin-up domain expansion when the FEL spot (macropulse energy: 8 mJ) scans on the sample surface.…”

“…(b) Active area of domain flipping is off from the center of the laser spot. Reproduced with permission from Ref [229]…”

Multi-Pass Free Electron Laser Assisted Spectral and Imaging Applications in the Terahertz/Far-IR Range Using the Future Superconducting Electron Source BriXSinO

“…Mechanisms driven by intense THz electromagnetic fields in spin systems recently gained great interest in modern spintronics as a novel way to obtain ultrafast control in macroscopic magnetization. Observation on the reconfiguration dynamics of magnetic domain structures under high field THz FEL pulses by Kurihara et al [112] has proven the possible use of realizing thermal spin effects at this frequency range. To irradiate the ferromagnetic domains of single crystal ErFeO 3 , authors use intense (10 mJ/pulse) THz pulses generated by the FEL.…”