Evidence of Frozen Moments at Low T in κ-(BEDT-TTF)<sub>2</sub>Hg(SCN)<sub>2</sub>Br

ORAL

Abstract

Quantum Spin Liquids (QSLs) and the phenomena behind their manifestation continue to be a topic of debate in solid state physics. The charge transfer salt, κ-(BEDT-TTF)2Hg(SCN)2Br or (κ-HgBr), has been proposed as a “quantum dipole liquid” [1], possibly exhibiting the necessary properties for QSL emergence. We examine the magnetic properties of κ-HgBr using 13C NMR Spectroscopy. 1/T1 measurements show a first order transition at TMI = 90 K, a possible crossover at T = 20 K, and a pronounced peak at 5 K characteristic of freezing moments. Analysis of the NMR spectra reveals an onset of broadening at TMI which becomes more pronounced at low T reaching a FWHM of approximately 1350 ppm at T = 2.5 K. The behavior and magnitude of the linewidth with respect to temperature is indicative of coupling to electron moments which are gradually freezing as temperature decreases and agrees with the 1/T1 behavior.

[1] Hassan et al., Science 360, 1101–1104 (2018)

*This work was supported by the National Science Foundation (DMR-1709304).

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Presenters

  • Teresa Le

    • University of California, Los Angeles

Authors

  • Teresa Le

    • University of California, Los Angeles

  • Andrej Pustogow

    • University of California, Los Angeles

  • Jierong Wang

    • Physics, Nanjing University

  • Alyssa Henderson

    • Natl High Magnetic Field Lab
    • Florida State University

  • John A Schlueter

    • National Science Foundation
    • Division of Materials Research, National Science Foundation
    • Division of Material Research, National Science Foundation

  • Stuart Brown

    • University of California, Los Angeles