Title: Topological Maxwell Metal Bands in a Superconducting Qutrit,
Abstract: We experimentally explore the topological Maxwell metal bands by mapping the
momentum space of condensed-matter models to the tunable parameter space of
superconducting quantum circuits. An exotic band structure that is effectively
described by the spin-1 Maxwell equations is imaged. Three-fold degenerate
points dubbed Maxwell points are observed in the Maxwell metal bands. Moreover,
we engineer and observe the topological phase transition from the topological
Maxwell metal to a trivial insulator, and report the first experiment to
measure the Chern numbers that are higher than one.