Encoding functional nanocircuits into ferroelectric photonics

Monolithic integration of electronic functionality into insulating ferroelectric photonic platforms remains a critical challenge. We introduce a paradigm in which ferroelectric domain walls (DWs) are engineered as active, programmable nanocircuits rather than passive boundaries. Using a single-step nanofabrication process, we directly encode a conductive DW network into thin-film lithium tantalate (TFLT), spatially coincident with a co-designed optical metasurface. This tailored superlattice enables quantum-tunneling-governed transport with a record-low resistivity of around 2.6×10−4 Ω·m. The synergy between the resonant metasurface and the embedded nanocircuit yields a high-performance, self-powered photodetector at the design resonant wavelength (785 nm), exhibiting a responsivity of 0.84 A/W and a response time as small as 160 μs. We transform domain engineering from a structural tool into a functional design platform, embedding tailored optoelectronic circuitry into passive photonics for next-generation multifunctional systems.