  The Weyl particle is the massless fermionic cousin of the photon. While no
fundamental Weyl particles have been identified, they arise in condensed matter
and meta-material systems, where their spinor nature imposes topological
constraints on low-energy dispersion and surface properties. Here we
demonstrate a topological circuit with Weyl dispersion at low-momentum,
realizing a 3D lattice that behaves as a half-flux Hofstadter model in all
principal planes. The circuit platform provides access to the complete
complex-valued spin-texture of all bulk- and surface- states, thereby revealing
not only the presence of Weyl points and the Fermi arcs that connect their
surface-projections, but also, for the first time, the Berry curvature
distribution through the Brillouin zone and the associated quantized Chiral
charge of the Weyl points. This work opens a path to exploration of interacting
Weyl physics in superconducting circuits, as well as studies of how manifold
topology impacts band topology in three dimensions.
