Excitations from a Bose-Einstein condensate of magnons in coupled spin ladders.

ORAL

Abstract

The weakly coupled quasi-one-dimensional spin ladder compound (CH$_3$)$_2$CHNH$_3$CuCl$_3$ is studied by neutron scattering in magnetic fields exceeding the critical field of Bose-Einstein condensation of magnons. Commensurate long-range order and the associated Goldstone mode are detected and found to be similar to those in a reference 3D quantum magnet. However, for the upper two massive magnon branches the observed behavior is totally different, culminating in a drastic collapse of excitation bandwidth beyond the transition point.

*Research at ORNL was funded by the United States Department of Energy, under Contract No. DE-AC05-00OR22725 with UT-Battelle, LLC.

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Authors

  • Andrey Zheludev

    • Oak Ridge National laboratory

  • Ovidue Garlea

    • Oak Ridge National Laboratory

  • Takatsugu Masuda

    • Yokohama City University, Japan

  • Hirotaka Manaka

    • Kagoshima University, Japan

  • Louis-Pierre Regnault

    • CEA Grenoble, France

  • Jae-Ho Chung

    • NIST, Gaithersburg, MD, USA

  • Yiming Qiu

    • NIST, Gaithersburg, MD, USA

  • Klaus Habicht

    • Hahn Meitner Institut, Berlin, Germany

  • Klaus Kiefer

    • Hahn Meitner Institut, Berlin, Germany