Resolving Continua of Fractional Excitations by Spinon Echo in THz 2D Coherent Spectroscopy

Journal Article · 25 June 2019 · Physical Review Letters

DOI: https://doi.org/10.1103/physrevlett.122.257401 · OSTI ID:1613184

Wan, Yuan ^[1]; Armitage, N. P. ^[2]

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1. Chinese Academy of Sciences (CAS), Beijing (China)
2. Johns Hopkins Univ., Baltimore, MD (United States); Univ. of Tokyo, Kashiwa (Japan)

We show that the new technique of terahertz 2D coherent spectroscopy is capable of giving qualitatively new information about fractionalized spin systems. For the prototypical example of the transverse field Ising chain, we demonstrate theoretically that, despite the broad continuum of excitations in linear response, the 2D spectrum contains sharp features that are a coherent signature of a “spinon echo,” which gives previously inaccessible information such as the lifetime of the two-spinon excited state. Here, the effects of disorder and finite lifetime, which are practically indistinguishable in the linear optical or neutron response, manifest in dramatically different fashion in the 2D spectra. Our results may be directly applicable to model quasi-1D transverse field Ising chain systems such as CoNb₂O₆, but the concept can be applied to fractionalized spin systems in general.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Institute for Quantum Matter (IQM); Johns Hopkins Univ., Baltimore, MD (United States)
• Sponsoring Organization: USDOE Office of Science (SC); USDOE
• Grant/Contract Number: SC0019331
• OSTI ID: 1613184
• Alternate ID(s): OSTI ID: 1529428; OSTI ID: 1826654
• Journal Information: Physical Review Letters, Vol. 122, Issue 25; ISSN 0031-9007
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English