Probing non-equilibrium topological order on a quantum processor.

Will, M; Cochran, T A; Rosenberg, E; Jobst, B; Eassa, N M; Roushan, P; Knap, M; Gammon-Smith, A et al. · Nature · 2025

basic_science · Level V

Where this comes from

Abstract

Out-of-equilibrium phases in many-body systems constitute a new paradigm in quantum matter-they exhibit dynamical properties that may otherwise be forbidden by equilibrium thermodynamics. Among these non-equilibrium phases are periodically driven (Floquet) systems<sup>1-5</sup>, which are generically difficult to simulate classically because of their high entanglement. Here we realize a Floquet topologically ordered state theoretically proposed in ref. <sup>6</sup>, on an array of superconducting qubits. We image the characteristic dynamics of its chiral edge modes and characterize its emergent anyonic excitations. Devising an interferometric algorithm allows us to introduce and measure a bulk topological invariant to probe the dynamical transmutation of anyons for system sizes up to 58 qubits. Our work demonstrates that quantum processors can provide key insights into the thus-far largely unexplored landscape of highly entangled non-equilibrium phases of matter.