Reduced fidelity in topological quantum phase transitions

TL;DR

This paper demonstrates that reduced fidelity, a local measure, can effectively signal topological quantum phase transitions by analyzing local states in lattice systems with topological order, using analytical methods.

Contribution

It introduces an analytical approach to connect reduced fidelity with topological phase transitions, showing its effectiveness as a local marker.

Findings

Reduced fidelity scales predictably at topological transitions.

Reduced fidelity reliably indicates topological phase changes.

Analytical methods link local states to global topological order.

Abstract

We study the reduced fidelity between local states of lattice systems exhibiting topological order. By exploiting mappings to spin models with classical order, we are able to analytically extract the scaling behavior of the reduced fidelity at the corresponding quantum phase transitions out of the topologically ordered phases. Our results suggest that the reduced fidelity, albeit being a local measure, generically serves as a faithful marker of a topological quantum phase transition.