Superpotential enhanced superconductivity and robust stiffness shaped by quantum geometry

Abstract

Abstract

Abstract Enhancing superconductivity through material design is a central goal in quantum materials research. Moiré engineering, where twisting stacked layers creates long-wavelength modulations and flat bands, amplifies electronic correlations and raises the superconducting critical temperature T c , but is largely confined to van der Waals materials with limited tunability. Here we explore an alternative: imposing artificial superpotentials on homogeneous systems to engineer flat minibands. We show that a periodic superpotential in a two-dimensional system enhances superconductivity by reconstructing electronic bands and creating regions of large density of states, substantially increasing T c . Unlike conventional flat-band systems, where superfluid stiffness arises solely from quantum geometry, a modulated system also inherits kinetic energy from filled minibands below the Fermi level, coexisting with a positive quantum geometric contribution to yield finite, robust stiffness. The resulting state remains resilient against weak to moderate disorder. These findings establish superlattice engineering as a tunable route to enhanced superconductivity beyond twist-based moiré systems, and a promising platform for next-generation superconductors.