  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 Bi2212 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.
