Wydarzenie w dniu 21.11.2025:
SEMINARIUM
Zakładów Naukowych ZN2, ZN3, ZN5
Dnia: 21.11.2025 roku (piątek)
o godzinie 10:00 Online
referat pt.:
Describing currents of orbital angular momentum with scattering theory
wygłosi
University of Twente
Describing currents of orbital angular momentum with scattering theory
With a view to understanding the role of various types of disorder in the orbital Hall effect, we extend quantum mechanical scattering calculations to generate and study currents of orbital angular momentum (OAM). The orbital Hall conductivities that we find have the same order of magnitude as found in other theoretical work, with little dependence on thermal lattice disorder and considerably more structure as a function of energy which largely tracks the density of states [1].
From the decay of a fully spin-polarized current injected into a thermally disordered scattering region we determined the spin-flip diffusion length lsf and interface spin memory loss parameter δ for various systems of experimental interest. For the 5d transition metal elements, values of lsf ranging from 3 to 50 nm were found at room temperature [2]. By contrast, currents of OAM are found to decay on a length scale of the electronic interatomic hopping, shorter than a nanometre [3]. They can convert to spin-currents at an interface leading to the suggestion that the large length scale extracted from experiment may in fact be lsf.
[1] M. Rang and P.J. Kelly, Physical Review B 111, 125121 (2025).
[2] R.S. Nair, E. Barati, K. Gupta, Z. Yuan and P.J. Kelly, Physical Review Letters 126, 196601 (2021).
[3] M. Rang and P.J. Kelly, Physical Review B 109, 214427 (2024).