Wilson ratio of a Tomonaga-Luttinger liquid in a spin-1/2 Heisenberg ladder

ORAL

Abstract

We report a comprehensive study of a strong-leg spin-1/2 ladder compound (C7H10N)2CuBr4 (DIMPY) by specific heat, magnetocaloric effect, magnetization and inelastic neutron scattering measurements. DIMPY is shown to be a perfect one-dimensional Heisenberg antiferromagnet with a spin gap$=$0.32 meV. Above a critical field Hc and at temperature below 1 K, the specific heat exhibits asymptotic linear-T behavior, characteristic of a Tomonaga-Luttinger liquid (TLL). In this field and temperature region, the specific heat in conjunction with the susceptibility yields the Wilson ratio $R_{W}$. The result supports the relation $R_{W}=$4$K$, where $K$ is the TLL parameter.

*The work at ORNL was partially supported by the Division of Scientific User Facilities, Office of BES, DOE.

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Authors

  • Tao Hong

    • Quantum Condensed Matter Division, Oak Ridge National Laboratory

  • K. Ninios

    • University of Florida

  • Y.H. Kim

    • University of Florida

  • T. Manabe

    • Kyoto Sangyo University

  • C. Hotta

    • Kyoto Sangyo University

  • G. Tremelling

    • Clark University

  • S.N. Herringer

    • Clark University

  • M.M. Turnbull

    • Clark University

  • C. Landee

    • Clark University

  • H.-J. Kang

    • NIST

  • K.P. Schmidt

    • TU Dortmund

  • G.S. Uhrig

    • TU Dortmund

  • H.B. Chan

    • University of Florida

  • C. Broholm

    • The Johns Hopkins University

  • Y. Takano

    • University of Florida