  We report a microscopic electronic mechanism for nanoscale skyrmion formation
and topological metalicity. The mechanism, which relies on combining the
classic double-exchange (DE) physics with the Rashba spin orbit coupling (SOC),
not only provides an accurate understanding of existence of skyrmions but also
explains key features in small angle neutron scattering (SANS) and Lorentz
transmission electron microscopy (LTEM) data on thin films of a variety of
magnetic metals. The skyrmion states are characterized as disordered
topological metals via explicit calculations of Bott index and Hall
conductivity. Local density of states (LDOS) display characteristic
oscillations that are shown to be arising from a combination of confinement
effect and gauge-field induced Landau level physics. The presence of
oscillations in LDOS, without external magnetic flux, is a direct consequence
of the Rashba-Zener (RZ) mechanism. The results are based on hybrid simulations
on a model that explicitly retains itinerant electronic degrees of freedom. A
simple physical picture is provided via an effective short-range spin model
with coupling constants that depend on electronic kinetic energy. The mechanism
reported here not only opens up a new approach to understand skyrmion formation
in metals, but also provides a guiding principle for discovering exotic
topological metal states.
