Tunable transport and multistate memory based on domain-wall engineering in bilayer α -In2Se3

Neuromorphic computing demands devices integrating sensing, computing, and memory to bypass traditional bottlenecks, with multiple nonvolatile states as a key characteristic—yet atomic-scale realization remains elusive. Using first-principles calculations combined with the nonequilibrium Green's function method, we investigate the quantum transport properties of devices composed of distinct domains in bilayer α-In2Se3 and achieve six nonvolatile conductance states under a small bias of 0.1 V. The transport mechanism is governed by both domains and domain walls. The transition from a single conduction channel to dual channels is enabled by domain modulation-induced changes in the spatial distribution of electronic states in the conduction and valence bands. Concurrently, domain-wall engineering allows the Fermi level to surpass the potential barrier, effectuating a transformation from tunneling to direct conduction. This work provides theoretical insights for designing ultrathin neuromorphic devices based on two-dimensional ferroelectrics.