[18p-221B-1~15] 4.6 Terahertz Photonics

▼ [18p-221B-4] Terahertz emission from ferromagnetic Co/Pt heterostructures

〇(DC)Hongsong Qiu¹, Kosaku Kato¹, Kazumasa Hirota¹, Nobuhiko Sarukura¹, Masashi Yoshimura¹, Makoto Nakajima¹ (1.Osaka Univ.)

Keywords:terahertz emission, spin current, ferromagnetic heterostructure

The terahertz emission based on the spin current in the ferromagnetic heterostructure Co/Pt is demonstrated. The spin current launched by the NIR femtosecond laser pulse is injected from Co to Pt layer and converted into the in-plane charge current due to the inverse spin Hall effect, which gives rise to the terahertz emission into the free space. The inverse spin Hall effect occurs within a nano-scale thickness range, and the appropriate thickness has not been reported. We studied the Pt-layer thickness dependence in the experiment. Our model that includes the effect of the spin current transport in the bulk material and the spin loss at the interface of the heterostructure quantitatively reproduces the experimental results.