  A comprehensive mapping of the spin polarization of the electronic bands in
ferroelectric a-GeTe(111) films has been performed using a time-of-flight
momentum microscope equipped with an imaging spin filter that enables a
simultaneous measurement of more than 10.000 data points (voxels). A Rashba
type splitting of both surface and bulk bands with opposite spin helicity of
the inner and outer Rashba bands is found revealing a complex spin texture at
the Fermi energy. The switchable inner electric field of GeTe implies new
functionalities for spintronic devices.
