Electron spin orientation dependence on momentum in pseudo gap phase of Bi۲۲۱۲

The aim of the paper is to study the electron spin direction dependence on momentum due to the presence of Rashba spin-orbit coupling in the pseudo-gap phase of Bi۲۲۱۲ bilayer. The non-trivial spin texture in k-space is found tuneable by electric field. The dependence is reported earlier by a group of workers in a spin-and angle-resolved photoemission spectroscopic measurement. The synthetic spin-orbit coupling, characterized by the broken time-reversal symmetry, is expected to be useful for the manipulation of the spin orientation.