Reduced fidelity in Kitaev honeycomb model

TL;DR

This paper demonstrates that reduced fidelity susceptibility effectively signals quantum phase transitions in the Kitaev honeycomb model, serving as a local marker for topological phase changes.

Contribution

It shows that two-site reduced fidelity susceptibility peaks at the phase transition, unlike one-site susceptibility, highlighting its usefulness in characterizing topological quantum phase transitions.

Findings

Two-site reduced fidelity susceptibility peaks at the transition point.

One-site reduced fidelity susceptibility vanishes at the transition.

Reduced fidelity susceptibility can characterize topological phase transitions.

Abstract

We study the reduced fidelity and reduced fidelity susceptibility in the Kitaev honeycomb model. It is shown that the reduced fidelity susceptibility of two nearest site manifest itself a peak at the quantum phase transition point, although the one-site reduced fidelity susceptibility vanishes. Our results directly reveal that the reduced fidelity susceptibility can be used to characterize the quantum phase transition in the Kitaev honeycomb model, and thus suggest that the reduced fidelity susceptibility is an accurate marker of the topological phase transition when it is properly chosen, despite of its local nature.