Luttinger liquid physics in the spin ladder material CuBr4(C5H12N)2

M. Klanjšek (1) , H. Mayaffre (2) , C. Berthier (3) , M. Horvatić (3) , B. Chiari (4) , O. Piovesana (4) , P. Bouillot (5) , C. Kollath (6) , Edmond Orignac (7) , R. Citro (8) , T. Giamarchi (5)

1 IJS - Jozef Stefan Institute [Ljubljana]
2 LSP - Laboratoire de Spectrométrie Physique
3 LNCMI-G - Laboratoire national des champs magnétiques intenses - Grenoble
4 Dipartimento di Chimica [Perugia]
5 UNIGE - Université de Genève = University of Geneva
6 CPHT - Centre de Physique Théorique [Palaiseau]
7 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
8 Dipartimento di Fisica "E. R. Caianiello" and CNISM

We present a 14N nuclear magnetic resonance study of a single crystal of CuBr4(C5H12N)2 consisting of weakly coupled spin-1/2 Heisenberg antiferromagnetic ladders. When placed in a magnetic field, such a ladder is theoretically predicted to exhibit a quantum critical Luttinger liquid (LL) behaviour in the gapless phase, i.e. between the two critical fields. Treating ladders as LLs and interaction between them as a perturbation, we are indeed able to fully account for (i) the spin dynamics accessed by measuring the spin–lattice relaxation rate equation image, and for (ii) the phase transition to a 3D ordered phase occurring below 110 mK due to the weak interladder coupling.

Keywords: spin ladder; Luttinger liquid; NMR; field induced phase transitions

Domains: Physics [physics]; Condensed Matter [cond-mat]; Strongly Correlated Electrons [cond-mat.str-el]

M. Klanjšek, H. Mayaffre, C. Berthier, M. Horvatić, B. Chiari, et al.. Luttinger liquid physics in the spin ladder material CuBr4(C5H12N)2. Quantum Criticality and Novel Phases (QCNP 2009), Frank Steglich, Oliver Stockert and Steffen Wirth, Aug 2009, Dresden, Germany. pp.656-658, ⟨10.1002/pssb.200983048⟩. ⟨ensl-00565064⟩