Magnetochiral anisotropy induced nonreciprocal transport in Si/SiO_x/ZnO heterostructures: a path to advanced...

Although magnetochiral-anisotropy-induced NCT has been largely restricted to in-plane magnetic fields, we demonstrate NCT response across both in-plane and out-of-plane directions in a Si/SiO_x/ZnO heterostructure. The magnitude and behavior of the NCT response, as well as the associated bilinear and quadratic magnetoresistance in Si/SiO_x/ZnO heterostructures, are highly sensitive to the interplay between thermal effects, magnetic field strength and orientation, and ZnO film structure. The relative amplitudes of the bilinear and quadratic components reveal a transition from semiclassical to quantum-dominated transport. NCT is a rectification-like phenomenon that enables precise modulation of unidirectional conduction; however, it is forbidden in centrosymmetric systems. A standardized NCT coefficient (γ') of 3.6 × 10^-7 A^-1 T^-1 m² is achieved in a meticulously engineered Si/SiO_x/5.6 nm ZnO heterostructure at 160 K. The pronounced NCT observed in these heterostructures originates from structural inversion asymmetry at the SiO_x-ZnO interface, which induces Rashba spin-orbit coupling. This leads to spin-momentum locking and chiral transport within the heterostructure, while the spin-orbit interaction also enhances asymmetric skew scattering. The robust, tunable NCT response across all three orientations provides a platform for developing precise, direction-sensitive sensors that enable accurate magnetic field detection, low-power nonlinear rectification, and directional differentiation in complex electromagnetic environments.