Fermionic excitations in the spin liquid phase of Cs$_2$CuCl$_4$ as revealed by $^{133}$Cs NMR

ORAL

Abstract

Nuclear magnetic resonance measurements of the spin-liquid phase of the spin-1/2 frustrated antiferromagnet Cs$_2$CuCl$_4$ as a function of temperature and applied magnetic field will be presented. Comparison of the magnetization and relaxation rate to the spin-1/2 antiferromagnetic chain $\alpha$-CuNSal and to variational calculations using Gutzwiller-projected mean-field theory implies that the low energy excitations in Cs$_2$CuCl$_4$ are characterized, in the spin liquid phase at non-zero temperature and applied field, by gapless fermionic excitations. Furthermore, interactions in two dimensions are required to reproduce the low energy properties.

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Authors

  • Vesna F. Mitrovic

    • Brown University

  • Marc-Andre Vachon

    • Brown University

  • Georgios Koutroulakis

    • Brown University

  • Ookie Ma

    • Brown University

  • Brad Marston

    • Brown University

  • Arneil P. Reyes

    • NHMFL

  • Philip Kuhns

    • NHMFL

  • Radu Coldea

    • Clarendon Laboratory, University of Oxford

  • T. Tylczynski

    • Institute of Physics, Adam Mickiewicz University