Controlling Luttinger Liquid Physics in Spin Ladders under Magnetic Field

ORAL

Abstract

We present a $^{14}$N nuclear magnetic resonance study of a single crystal of CuBr$_4$(C$_5$H$_{12}$N)$_2$ (BPCB) consisting of weakly coupled spin-$1/2$ Heisenberg antiferromagnetic ladders. Treating ladders in the gapless phase as Luttinger liquids, we are able to fully account for (i) the magnetic field dependence of the nuclear spin-lattice relaxation rate $T_1^{-1}$ at $250$~mK and for (ii) the phase transition to a 3D ordered phase occuring below $110$~mK due to weak inter-ladder exchange coupling. BPCB is thus an excellent model system where the possibility to control Luttinger liquid parameters in a continuous manner is demonstrated and Luttinger liquid model tested in detail over the whole fermion band.\\ M. Klanj\v{s}ek {\em et al.}, Phys. Rev. Lett. {\bf 101} 137207 (2008).

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Authors

  • C. Berthier

  • M. Klanj\v{s}ek

  • M. Horvati\'{c}

    • GHMFL, CNRS, F-38042 Grenoble Cedex 09, France

  • H. Mayaffre

    • LSP, Univ. J. Fourier \& UMR5588 CNRS, F-38402 Saint Martin d H\`{e}res, France

  • B. Chiari

  • O. Piovesana

    • Dip. di Chimica, Univ. di Perugia, I-06100 Perugia, Italy

  • P. Bouillot

  • T. Giamarchi

    • DPMC-MaNEP, Univ. of Geneva, CH-1211 Geneva, Switzerland

  • C. Kollath

    • CPHT, Ecole Polytechnique, CNRS, 91128 Palaiseau, France
    • CNRS, Ecole Polytechnique, France
    • CPTH, Ecole Polytechnique, CNRS, F-91128 Palaiseau Cedex, France

  • E. Orignac

    • LPENSL CNRS UMR 5672, F-69364 Lyon Cedex 07, France

  • R. Citro

    • Universit\`a degli Studi di Salerno, Dipartimento di Fisica ``E. R. Caianiello'', 84081 Baronissi (Sa), Italy
    • Universit\`a di Salerno, Italy
    • Dip. di Fisica , Univ. di Salerno, I-84081 Baronissi (Sa), Italy