Surface spin polarization in the magnetic response of GeTe Rashba ferroelectric
A. A. Avakyants, N. N. Orlova, A. V. Timonina, N. N. Kolesnikov, E. V. Deviatov
Institute of Solid State Physics of the Russian Academy of Sciences, 142432 Chernogolovka, Russia
Abstract
We experimentally investigate magnetization reversal curves for a GeTe topological semimetal.
In addition to the known lattice diamagnetic response, we observe narrow magnetization loop in low fields,
which should not be expected for non-magnetic material. The diamagnetic hysteresis loop is unusual, so the saturation
level is negative in positive fields, and the loop is passed clockwise, in contrast to standard ferromagnetic behavior.
We show, that the experimental hysteresis curves can not be obtained from standard ferromagnetic ones by
adding/subtracting of any linear dependence, or even by considering several interacting magnetic phases. The latter possibility
is also eliminated by the remanence plots technique (Henkel or δ M plots). We explain our results as a direct
consequence of the correlation between ferroelectricity and spin-polarized surface states in GeTe, similarly to
magnetoelectric structures.