Probing entanglement dynamics and topological transitions on noisy intermediate-scale quantum computers

TL;DR

This paper demonstrates the simulation of topological quench dynamics and entanglement measures on noisy IBM quantum computers, revealing oscillations and transitions with error mitigation techniques.

Contribution

It introduces a method to measure topological and entanglement properties without extra gates or ancillas on NISQ devices, applied to the SSH model.

Findings

Successful measurement of entanglement entropy, twist order parameter, and Berry phase on IBM quantum computers.

Observation of persistent oscillations in entanglement and topological indicators during quenches.

Error mitigation techniques significantly improve the accuracy of quantum simulations.

Abstract

We simulate quench dynamics of the Su-Schrieffer-Heeger (SSH) chain on the IBM quantum computers, calculating the R\'enyi entanglement entropy, the twist order parameter and the Berry phase. The latter two quantities can be deduced from a slow-twist operator defined in the Lieb-Schultz-Mattis theorem. The R\'enyi entropy is obtained using a recently developed randomized measurement scheme. The twist order parameter and the Berry phase are measured without the need for additional gates or ancilla qubits. We consider quench protocols in which a trivial initial state evolves dynamically in time under the topological SSH Hamiltonian in the fully dimerized limit (the flat-band limit). During these quenches, there are persistent and periodic oscillations in the time evolution of both entanglement entropy and twist order parameter. Through the implementation of error mitigation techniques using a global depolarizing ansatz and postselection, our simulations on the IBM devices yield results that closely match exact solutions.