Reversible and Nonvolatile Manipulation of the Spin-Orbit Interaction in Ferroelectric Field-Effect Transistors Based on a Two-Dimensional Bismuth Oxychalcogenide

The spin-orbit interaction (SOI) offers a nonferromagnetic scheme to realize spin polarization through utilizing an electric field. Electrically tunable SOIs through electrostatic gates have been investigated; however, the relatively weak and volatile tunability limits their practical applications in spintronics. Here, we demonstrate the nonvolatile electric field control of the SOI via constructing ferroelectric Rashba architectures, i.e., two-dimensional Bi2O2Se/Pb (Mg1/3Nb2/3)O-3-PbTiO3 ferroelectric field-effect transistors. The experimentally observed weak antilocalization (WAL) cusp in Bi2O2Se films implies the Rashbatype SOI that arises from the asymmetric confinement potential. Significantly, taking advantage of the switchable ferroelectric polarization, the WAL-to-weak-localization-transition trend reveals the competition between spin relaxation and the dephasing process, and the variation of carrier density leads to a reversible and nonvolatile modulation of the spin-relaxation time and the spin-splitting energy of Bi2O2Se films by this ferroelectric gating. Our work provides a scheme to achieve nonvolatile control of the Rashba SOI with the utilization of ferroelectric remanent polarization.