Spin dynamics in the triangular-lattice antiferromagnet Cs$_2$CuBr$_4$

ORAL

Abstract

We present results of our recent electron spin resonance (ESR) studies of Cs$_2$CuBr$_4$, a spin-1/2 Heisenberg antiferromagnet with a distorted triangular-lattice structure, in magnetic fields up to 50 T. Studying the magnetic excitation spectrum in the magnetically saturated phase ($H_{sat} \sim 30$ T) allowed us to accurately determine exchange parameters of Cs$_2$CuBr$_4$. In addition, we report on the observation of a substantial zero-field gap, $\sim 10$ K, whose origin will be discussed. The peculiarities of the ESR spectrum above and below $H_{sat}$ are described taking into account the effect of the Dzyaloshinskii-Moriya interaction.

*This work was supported by DFG, Germany. We acknowledge the support of the HLD at HZDR, member of the European Magnetic Field Laboratory. S.Z. appreciates the support of the VPP at KYOKUGEN in Osaka University

–

Authors

  • S. Zvyagin

    • HLD-HZDR, Germany

  • E. Schulze

    • HLD-HZDR, Germany

  • A. Ponomaryov

    • HLD-HZDR, Germany

  • J. Wosnitza

    • HLD-HZDR, Germany

  • M. Ozerov

    • Radboud University Nijmegen, The Netherlands

  • D. Kamenskyi

    • Radboud University Nijmegen, The Netherlands

  • J. Krzystek

    • NHMFL-FSU, USA

  • D. Yoshizawa

    • Osaka University, Japan

  • M. Hagiwara

    • Osaka University, Japan

  • R. Hu

    • Brookhaven National Laboratory, USA and Stony Brook University, USA

  • H. Ryu

    • Brookhaven National Laboratory, USA

  • Cedomir Petrovic

    • Brookhaven National Laboratory, USA
    • Brookhaven Natl Lab

  • M. Zhitomirsky

    • CEA-INAC/UJF, France