Diagnosing Quantum Phases Using Long-Range Two-Site Quantum Resource Behaviors

TL;DR

This paper demonstrates that analyzing long-range two-site quantum resources like coherence and discord can effectively diagnose various quantum phases, including spin-liquid and topological phases, revealing phenomena like resource freezing.

Contribution

It introduces a novel method using long-range quantum resource behaviors to identify quantum phases, including topological ones, with analytical and numerical support.

Findings

Quantum coherence and discord reveal quantum phase transitions.

Long-range entanglement confirmed via correlation functions.

Discovery of quantum resource freezing in topological phases.

Abstract

We propose and demonstrate that the behaviors of long-range, two-site quantum resources can effectively diagnose quantum phases. In an XX spin chain with symmetry-breaking quantum phase transitions, we reveal that the asymptotic and oscillating decay modes of quantum coherence or quantum discord, along with two-site distance, can identify two spin-liquid phases. Furthermore, based on our analytical results of spin correlation functions, we confirm the existence of long-range entanglement in the system and establish a connection between two-site entanglement and quantum phases. Additionally, for the extended Ising model with topological phase transitions, we find that coherence and quantum discord behaviors can also signify topological quantum phases. In particular, we discover the quantum resource freezing phenomenon, where topologically protected long-range quantum resources may have potential applications in quantum information processing.