4 research outputs found
Influence of anti-site disorder and electron-electron correlations on the electronic structure of CeMnNi
CeMnNi exhibits an unusually large spin polarization, but its origin has
baffled researchers for more than a decade. We use bulk sensitive hard x-ray
photoelectron spectroscopy (HAXPES) and density functional theory based on the
Green's function technique to demonstrate the importance of electron-electron
correlations of both the Ni 3 () and Mn 3 () electrons in
explaining the valence band of this multiply correlated material. We show that
Mn-Ni anti-site disorder as well as play crucial role in enhancing its
spin polarization: anti-site disorder broadens a Ni 3 minority-spin peak
close to the Fermi level (), while an increase in shifts it
towards , both leading to a significant increase of minority-spin states
at . Furthermore, rare occurrence of a valence state transition between
the bulk and the surface is demonstrated highlighting the importance of HAXPES
in resolving the electronic structure of materials unhindered by surface
effects.Comment: Manuscript and Supplementary material, 13 pages, 17 figure
Collective topological spin dynamics in a correlated spin glass
The interplay between spin-orbit interaction (SOI) and magnetic order is
currently one of the most active research fields in condensed matter physics
and leading the search for materials with novel and tunable magnetic and spin
properties. Here we report on a variety of unexpected and unique observations
in thin multiferroic \GeMnTe films. The ferrimagnetic order in this
ferroelectric semiconductor is found to reverse with current pulses six orders
of magnitude lower as for typical spin-orbit torque systems. Upon a switching
event, the magnetic order spreads coherently and collectively over macroscopic
distances through a correlated spin-glass state. Lastly, we present a novel
methodology to controllably harness this stochastic magnetization dynamics,
allowing us to detect spatiotemporal nucleation of topological spin textures we
term ``skyrmiverres''.Comment: 26 pages, 10 figures, 2 table