Dresden 2017 – wissenschaftliches Programm
MA 47.7: Vortrag
Donnerstag, 23. März 2017, 11:15–11:30, HSZ 04
Absence of detectable current-induced magneto-optical Kerr effects in Pt, Ta and W — •Patricia Riego1, Saül Vélez1, Juan M. Gomez-Perez1, Jon Ander Arregi1, Luis E. Hueso1,2, Fèlix Casanova1,2, and Andreas Berger1 — 1CIC nanoGUNE, San Sebastian (Spain) — 2Ikerbasque, Bilbao (Spain)
The direct detection of spin accumulation arising from the spin Hall effect (SHE) in metals via the magneto-optical Kerr effect (MOKE) would enable an easily accessible methodology for spintronics phenomena. Prior works have performed such measurements and have reported a successful outcome . Here, we explore such possibility by means of generalized magneto-optical ellipsometry (GME), a MOKE-based method that, in contrast to conventional MOKE measurement schemes, allows for a clear identification of the magneto-optical (MO) nature of the signal. We have performed measurements for three different materials: Pt, W, and Ta, and we observe a current-induced change in the light intensity in all of them. However, our complete GME analysis shows that such current-induced effects are not MO in nature, and therefore do not arise from a SHE-induced light polarization signal in any of the materials. Instead, they constitute a purely optical signal that arises from a heating-induced change in reflectivity. Based on the sensitivity achieved in our experiments, we conclude that state-of-the-art MO methods utilizing linear optics are not sufficiently sensitive to detect SHE-induced spin accumulation in these metals .
 O. M. J. van't Erve et al., Appl. Phys. Lett. 104, 172402 (2014).  P. Riego et al., Appl. Phys. Lett. 109, 172402 (2016).