ESR studies of the quasi-2D frustrated Cs2CuBr4

ORAL

Abstract

We report low-temperature electron spin resonance (ESR) studies of single-crystalline samples of Cs$_2$CuBr$_4$, a spin-1/2 antiferromagnet with a triangular spin-lattice structure. A remarkable angular dependence of the resonance field, including the splitting of the ESR line for some orientations of the magnetic field, and the presence of a gap in the ESR excitation spectrum at temperatures above $T_N\sim$ 1.3~K have been revealed. Our observations suggest that uniform Dzyaloshinskii-Moriya interaction affects the low-energy excitation spectrum in this frustrated compound. The results are compared with that obtained recently for the isostructural material Cs$_2$CuCl$_4$ [Povarov et al., Phys. Rev. Lett. 107, 037204 (2011)].

*The work was supported in part by DFG and EuroMagNET II (EU Contract No. 228043). *Present address: University of Maryland, Center for Nanophysics and Advanced Materials, College Pk, MD 20742 USA

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Authors

  • S.A. Zvyagin

    • HLD-HZDR, 01328 Dresden, Germany

  • D. Kamenskyi

    • HLD-HZDR, 01328 Dresden, Germany

  • J. Wosnitza

    • HLD-HZDR, 01328 Dresden, Germany

  • M. Ikeda

    • KYOKUGEN, Osaka University, Toyonaka, Osaka 560-8531, Japan

  • T. Fujita

    • KYOKUGEN, Osaka University, Toyonaka, Osaka 560-8531, Japan

  • M. Hagiwara

    • KYOKUGEN, Osaka University, Toyonaka, Osaka 560-8531, Japan

  • O.A. Starykh

    • Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA

  • *R. Hu

    • Condensed Matter Physics and Materials Science Department, BNL, Upton, NY 11973, USA

  • H. Ryu

    • Condensed Matter Physics and Materials Science Department, BNL, Upton, NY 11973, USA

  • C. Petrovic

    • Condensed Matter Physics and Materials Science Department, BNL, Upton, NY 11973, USA