Probing quantum spin liquids with multiple quantum coherences
Abstract
Quantum simulators are beginning to prepare long-sought phases of matter that remain difficult to realize cleanly in materials. Yet identifying such phases remains a major challenge when their defining properties are inherently non-local and cannot be captured by conventional local measurements. Here we establish multiple-quantum coherences (MQCs) as phase-sensitive diagnostics for gapped ℤ2 quantum spin liquids. Focusing on the extended toric code and using large-scale quantum Monte Carlo simulations, we build a direct correspondence between the elementary anyonic excitations and the weights of different MQC sectors. MQCs thereby reveal anyon condensation across the phase transitions through characteristic signatures that remain robust against fluctuations that obscure conventional diagnostics. Subsystem-resolved MQCs further provide a bipartite entanglement witness that distinguishes a classical loop gas from a quantum-coherent closed-loops gas. We develop and benchmark a practical protocol to extract MQCs based on the return fidelity of adiabatic round trips, and show that local coherence measurements retain experimentally accessible signatures of the phase transitions. Our results establish MQCs as a practical diagnostic for the excitations, phase structure and global constraints of quantum spin liquids.
Related
- Probing Coherences and Itinerant Magnetism in a Dipolar Lattice Gas
- Spinon-Induced Phonon Dynamics in Chiral and π-Flux Quantum Spin Liquids
- The influence of quantum geometry on the phase boundary and collective excitations of electron liquids and crystals
- Exact quantum spin liquids with topological order on maple-leaf and trellis lattices
- Topological Quantum Spin Liquids in a Ladder with Majorana fermions and p-wave Superconductivity
BibTeX
@misc{homeier2026probing,
title = {{Probing quantum spin liquids with multiple quantum coherences}},
author = {Lukas Homeier and Simon Linsel and Lode Pollet and Ana Maria Rey},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.25193},
eprint = {2609.25193},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.25193},
}
RIS
TY - UNPB
TI - Probing quantum spin liquids with multiple quantum coherences
AU - Lukas Homeier
AU - Simon Linsel
AU - Lode Pollet
AU - Ana Maria Rey
PY - 2026
DA - 2026/09/21
PB - arXiv
DO - 10.48550/arxiv.2609.25193
UR - https://arxiv.org/abs/2609.25193
AB - Quantum simulators are beginning to prepare long-sought phases of matter that remain difficult to realize cleanly in materials. Yet identifying such phases remains a major challenge when their defining properties are inherently non-local and cannot be captured by conventional local measurements. Here we establish multiple-quantum coherences (MQCs) as phase-sensitive diagnostics for gapped ℤ_2 quantum spin liquids. Focusing on the extended toric code and using large-scale quantum Monte Carlo simulations, we build a direct correspondence between the elementary anyonic excitations and the weights of different MQC sectors. MQCs thereby reveal anyon condensation across the phase transitions through characteristic signatures that remain robust against fluctuations that obscure conventional diagnostics. Subsystem-resolved MQCs further provide a bipartite entanglement witness that distinguishes a classical loop gas from a quantum-coherent closed-loops gas. We develop and benchmark a practical protocol to extract MQCs based on the return fidelity of adiabatic round trips, and show that local coherence measurements retain experimentally accessible signatures of the phase transitions. Our results establish MQCs as a practical diagnostic for the excitations, phase structure and global constraints of quantum spin liquids.
ER -