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.

–

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