Entanglement signatures of emergent Dirac fermions: Kagome spin liquid and quantum criticality

Journal Article · 08 November 2018 · Science Advances

DOI: https://doi.org/10.1126/sciadv.aat5535 · OSTI ID:1524391

Zhu, Wei  ^[1]; Chen, Xiao ^[2]; He, Yin-Chen ^[3]; Witczak-Krempa, William  ^[4]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Westlake Inst. of Advanced Study, Hangzhou (China)
2. Univ. of California, Santa Barbara, CA (United States)
3. Harvard Univ., Cambridge, MA (United States)
4. Univ. of Montreal, Quebec (Canada)

Quantum spin liquids (QSLs) are exotic phases of matter that host fractionalized excitations. It is difficult for local probes to characterize QSL, whereas quantum entanglement can serve as a powerful diagnostic tool due to its nonlocality. The kagome antiferromagnetic Heisenberg model is one of the most studied and experimentally relevant models for QSL, but its solution remains under debate. In this work, we perform a numerical Aharonov-Bohm experiment on this model and uncover universal features of the entanglement entropy. By means of the density matrix renormalization group, we reveal the entanglement signatures of emergent Dirac spinons, which are the fractionalized excitations of the QSL. This scheme provides qualitative insights into the nature of kagome QSL and can be used to study other quantum states of matter. As a concrete example, we also benchmark our methods on an interacting quantum critical point between a Dirac semimetal and a charge-ordered phase.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1524391
• Report Number(s): LA-UR-17-31500
• Journal Information: Science Advances, Journal Name: Science Advances Journal Issue: 11 Vol. 4; ISSN 2375-2548
• Publisher: AAASCopyright Statement
• Country of Publication: United States
• Language: English