Orbital splitter effect and spatial resolution of current-induced orbital accumulation
Phys. Rev. B 112, 014409 – Published 7 July, 2025
DOI: https://doi.org/10.1103/pzt5-5ypz
Abstract
The emergence of an orbital angular momentum (OAM) response to a charge current holds promise for technological applications, allowing electrical control of magnetization dynamics. Often, the OAM current is invoked in explaining experimental results for very large orbital transport effects, but this is conceptually challenging as the OAM current is not a conserved quantity. Instead of utilizing the orbital conductivity associated with the nonconserved OAM current, we here use nonequilibrium Green's functions to directly image the OAM density in real space under an applied electric current bias. We find strong spatial variations in OAM density, with the lattice acting as a source and sink of OAM. Moreover, we show that the OAM response depends sensitively on the angle between the charge current and the crystal axis. This enables the generation of a transverse OAM response in one current direction and solely a longitudinal response in another. We refer to this as an orbital splitter effect, analogous to the spin splitter effect in altermagnets.
