Experimental observation of topological transitions in interacting multi-spin systems

TL;DR

This paper reports the experimental observation of topological transitions in interacting multi-spin systems using NMR simulators, demonstrating the measurement of Berry curvature and Chern number in a quantum many-body context.

Contribution

It introduces a novel experimental approach to observe topological phase transitions in interacting quantum systems via NMR simulation.

Findings

Observation of interaction-induced topological transitions.

Measurement of Berry curvature in a many-body quantum system.

Extraction of the first Chern number from experimental data.

Abstract

Topologically ordered phase has emerged as one of most exciting concepts that not only broadens our understanding of phases of matter, but also has been found to have potential application in fault-tolerant quantum computation. The direct measurement of topological properties, however, is still a challenge especially in interacting quantum system. Here we realize one-dimensional Heisenberg spin chains using nuclear magnetic resonance simulators and observe the interaction-induced topological transitions, where Berry curvature in the parameter space of Hamiltonian is probed by means of dynamical response and then the first Chern number is extracted by integrating the curvature over the closed surface. The utilized experimental method provides a powerful means to explore topological phenomena in quantum systems with many-body interactions.