Nonreciprocal Transport in Superconducting Diodes via Tailored Antidot Geometries

The superconducting diode effect (SDE) offers a transformative path toward dissipationless nonreciprocal electronics, yet a unified framework for controlling its microscopic origins remains elusive. Here, we demonstrate precision engineering of the SDE in niobium films by tailoring the geometry of asymmetric micrometer-sized antidots. By decoupling transport responses under in-plane and out-of-plane magnetic fields, we identify a dual-mechanism regime: low-field rectification is governed by surface-barrier asymmetry (edge flux pinning), while high-field performance is driven by the intrinsic geometric landscape of the antidots (bulk flux pinning). Supported by time-dependent Ginzburg-Landau (TDGL) simulations and a robust analytical model, we establish a predictive design principle that links pinning topology to diode efficiency. These results provide a scalable strategy for developing tunable superconducting rectifiers, offering a critical building block for next-generation cryogenic logic and quantum information processing.