  Spin-orbit interaction (SOI) offers a nonferromagnetic scheme to realize spin
polarization through utilizing an electric field. Electrically tunable SOI
through electrostatic gates have been investigated, however, the relatively
weak and volatile tunability limit its practical applications in spintronics.
Here, we demonstrate the nonvolatile electric-field control of SOI via
constructing ferroelectric Rashba architectures, i.e., 2D Bi2O2Se/PMN-PT
ferroelectric field effect transistors. The experimentally observed weak
antilocalization (WAL) cusp in Bi2O2Se films implies the Rashba-type SOI that
arises from asymmetric confinement potential. Significantly, taking advantage
of the switchable ferroelectric polarization, the WAL-to-weak localization (WL)
transition trend reveals the competition between spin relaxation and dephasing
process, and the variation of carrier density leads to a reversible and
nonvolatile modulation of spin relaxation time and spin splitting energy of
Bi2O2Se films by this ferroelectric gating. Our work provides a scheme to
achieve nonvolatile control of Rashba SOI with the utilization of ferroelectric
remanent polarization.
