  The discovery of topological order has revolutionized the understanding of
quantum matter in modern physics and provided the theoretical foundation for
many quantum error correcting codes. Realizing topologically ordered states has
proven to be extremely challenging in both condensed matter and synthetic
quantum systems. Here, we prepare the ground state of the toric code
Hamiltonian using an efficient quantum circuit on a superconducting quantum
processor. We measure a topological entanglement entropy near the expected
value of $\ln2$, and simulate anyon interferometry to extract the braiding
statistics of the emergent excitations. Furthermore, we investigate key aspects
of the surface code, including logical state injection and the decay of the
non-local order parameter. Our results demonstrate the potential for quantum
processors to provide key insights into topological quantum matter and quantum
error correction.
