%0 Journal Article
%A Seifert, Tom S.
%A Go, Dongwook
%A Hayashi, Hiroki
%A Rouzegar, Reza
%A Freimuth, Frank
%A Ando, Kazuya
%A Mokrousov, Yuriy
%A Kampfrath, Tobias
%T Time-domain observation of ballistic orbital-angular-momentum currents with giant relaxation length in tungsten
%J Nature nanotechnology
%V 18
%N 10
%@ 1748-3387
%C London [u.a.]
%I Nature Publishing Group
%M FZJ-2023-05909
%P 1132 - 1138
%D 2023
%X The emerging field of orbitronics exploits the electron orbital momentum L. Compared to spin-polarized electrons, L may allow the transfer of magnetic information with considerably higher density over longer distances in more materials. However, direct experimental observation of L currents, their extended propagation lengths and their conversion into charge currents has remained challenging. Here, we optically trigger ultrafast angular-momentum transport in Ni|W|SiO2 thin-film stacks. The resulting terahertz charge-current bursts exhibit a marked delay and width that grow linearly with the W thickness. We consistently ascribe these observations to a ballistic L current from Ni through W with a giant decay length (~80 nm) and low velocity (~0.1 nm fs−1). At the W/SiO2 interface, the L flow is efficiently converted into a charge current by the inverse orbital Rashba–Edelstein effect, consistent with ab initio calculations. Our findings establish orbitronic materials with long-distance ballistic L transport as possible candidates for future ultrafast devices and an approach to discriminate Hall-like and Rashba–Edelstein-like conversion processes.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ 37550573
%U <Go to ISI:>//WOS:001043662300004
%R 10.1038/s41565-023-01470-8
%U https://juser.fz-juelich.de/record/1020242