Vectorial nanocurrents in emerging materials with nanostructured symmetries

A variety of photocurrent responses can emerge in the presence of broken material symmetries, either intrinsically at the atomic lattice scale, within applied fields, or via synthetic structuring. While light-based control over the linear and orbital moments of these currents down to nanometer spatial scales would open up many pathways for inducing and probing new physics in emerging materials, such control has been elusive. Here, we describe recent progress using synthetic symmetry breaking to control vectorial nanocurrents. Ultrafast thermodynamic energy and hydrodynamic momentum flows are explored for prototypical gold-graphene metasurfaces, with complex dynamics giving rise to simple, directional currents at each symmetry-broken gold nanoantenna. These results offer general insights for versatile nanocurrent control, and we examine some implications for other material systems.