Quantum Dynamical Characterization and Simulation of Topological Phases With High-Order Band Inversion Surfaces

How to characterize topological quantum phases is a fundamental issue in the broad field of topological matter. From a dimension reduction approach, we propose the concept of high-order band inversion surfaces (BISs), which enable the optimal schemes to characterize equilibrium topological phases by far-from-equilibrium quantum dynamics, and further report the experimental simulation. We show that characterization of a d-dimensional (dD) topological phase can be reduced to lower-dimensional topological invariants in the high-order BISs, of which the nth-order BIS is a (d - n)D interface in momentum space. In quenching the system from trivial phase to topological regime, we unveil a high-order dynamical bulk-surface correspondence that the quantum dynamics exhibits nontrivial topological pattern in arbitrary nth-order BISs, which universally corresponds to and so characterizes the equilibrium topological phase of the postquench Hamiltonian. This high-order dynamical bulk-surface correspondence provides new and optimal dynamical schemes with fundamental advantages to simulate and detect topological states, in which through the highest-order BISs that are of zero dimension, the detection of topological phase relies on only minimal measurements. We experimentally build up a quantum simulator with spin qubits to investigate a three-dimensional chiral topological insulator through emulating each momentum one by one and measure the high-order dynamical bulk-surface correspondence, with the advantages of topological characterization via highest-order BISs being demonstrated.

Automated summary

This study introduces the concept of high-order band inversion surfaces for characterizing equilibrium topological phases through far-from-equilibrium quantum dynamics and experimental simulation. By investigating the high-order BISs, it is shown that quantum dynamics can exhibit nontrivial topological patterns during quenching processes, corresponding to and characterizing the equilibrium topological phase. The high-order dynamical bulk-surface correspondence provides new and optimal schemes to detect and simulate topological states.