Polarization-induced ultrahigh Rashba spin-orbit interaction in ZnO/CdO quantum well

Highlights: • Rashba spin-orbit interaction (RSOI) of ZnO/CdO quantum well (QW) has been investigated. • Strain induced polarization of the QW adjusts the RSOI coefficient. • A maximum RSOI coefficient appears when varying external stress. • Ultrahigh RSOI coefficient has been unveiled by comparing a set of heterostructural QWs. Spin-orbit interaction (SOI) connecting an electronic spin with its momentum is crucial for numerous fundamental physical researches and their applications, including quantum spin Hall effect, Majorana Fermions and spin-orbit qubits. By breaking structural inversion symmetry, Rashba spin-orbit interaction (RSOI) provides an available method for the manipulation of spin by controlling electronic movement within external potential field. In this study, we demonstrate the RSOI of conduction electron modulated by stress-induced polarization field in ZnO/CdO quantum well (QW). The polarization field exactly triggers band inversion between the electron and light hole. The peak of RSOI coefficient can reach approximately up to 83 meV$\cdot$nm, almost three orders of magnitude higher than the conventional GaAs-based QWs. This study can be beneficial to sufficient manipulation of spin qubits by strong RSOI quantum piezotronic effect, and will stimulate an intense researching interest in low-dimensional quantum piezotronic devices.