Spinon-magnon interaction in an antiferromagnet with alternating antiferromagnetic and ferromagnetic quantum spin chains

POSTER

Abstract

The concepts of quasiparticles and collective modes have been successfully applied to describe low-energy excitations in physics. In conventional magnets low-energy excitations are carried by spin waves, represented by massless bosons called magnons with S = 1. However, in one-dimensional antiferromagnetic quantum spin (S = 1/2) systems, quantum fluctuations destroy LRO in the ground state and magnons do not exist. Instead, the low-energy excitations are known as spinons, with S = 1/2 . Although both magnons and two-spinon continuum have been observed in several quasi-one-dimensional antiferromagnets, magnons and spinons do not coexist in the same energy range. Here, we report the observation of coexistence of magnon and spinon excitations in Cu2(OH)3Br, a quantum antiferromagnet consisting of nearly decoupled, alternating ferromagnetic and antiferromagnetic S=1/2 chains. Importantly, the excitation spectra of both the magnetic chains emerge in close energy range and cross over each other, enabling strong spinon-magnon interaction.

Presenters

  • Heda Zhang

    • Michigan State Univ

Authors

  • Heda Zhang

    • Michigan State Univ

  • Zhiying Zhao

    • Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences
    • Fujian Institute of Research on the Structure of Matter, Chinese Academy of Science

  • Vasile O Garlea

    • Oak Ridge National Laboratory
    • Quantum Condensed Matter Div, Oak Ridge National Lab
    • Oak Ridge National Lab
    • Oak Ridge National Lab, Neutron Scattering Division

  • Tao Hong

    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Oak Ridge National Lab, Neutron Scattering Division

  • Dominique M Gautreau

    • University of Minnesota, Department of Chemical Engineering and Materials Science

  • Amartyajyoti Saha

    • University of Minnesota, Department of Chemical Engineering and Materials Science

  • S D Mahanti

    • Michigan State Univ
    • Michigan State University

  • Turan Birol

    • Chemical Engineering and Materials Science, University of Minnesota Twin Cities
    • University of Minnesota
    • Department of Chemical Engineering and Materials Science, University of Minnesota
    • University of Minnesota, Department of Chemical Engineering and Materials Science

  • Xianglin Ke

    • Michigan State Univ