Spin-resolved ARPES to distinguish between surface and bulk Rashba effect in PbTe and PbSe-based ferroelectric Rashba semiconductors

Beamtime at Synchrotron SOLARIS (URANOS), Krakau, Poland

Ferroelectric Rashba semiconductors (FERSCs) such as GeTe, Pb1-xGexTe, and Pb1-xGexSe are an important class of materials which exhibit a giant Rashba type spin splitting of ferroelectric origin.1-5 Therefore, the spin texture in these materials is programmable1,2 by switching the ferroelectric polarisation direction via applied electric fields. In order to bring FERSCs closer to their realization in spintronic devices, it is necessary to understand the effect of ferroelectric polarisation on the Rashba-type spin texture and distinguish it from the surface Rashba effect6-7 caused by the symmetry breaking and polar nature of the surface. This is proposed to be achieved in this proposal by utilizing spin-resolved ARPES to distinguish between the surface and bulk Rashba contributions and thus, finding out the relation between the direction
of the ferroelectric polarization and the spin texture in FERSCs.