Tomonaga-Luttinger Liquid Spin Dynamics in the Quasi-One-Dimensional Ising-Like Antiferromagnet BaCo 2 V 2 O 8

Quentin Faure (1, 2) , Shintaro Takayoshi (3) , Virginie Simonet (1) , Beatrice Grenier (2) , Martin Månsson (4) , Jonathan White (4) , Gregory Tucker (4) , Christian Rüegg (4) , Pascal Lejay (5) , Thierry Giamarchi (3) , Sylvain Petit (6)

1 NEEL - MagSup - Magnétisme et Supraconductivité
2 MDN - Magnétisme et Diffusion Neutronique
3 UNIGE - Université de Genève = University of Geneva
4 PSI - Paul Scherrer Institute
5 NEEL - C2MA - Croissance Cristalline et MicroAnalyse
6 LLB - UMR 12 - Laboratoire Léon Brillouin

Combining inelastic neutron scattering and numerical simulations, we study the quasi-one-dimensional Ising anisotropic quantum antiferromagnet BaCo2V2O8 in a longitudinal magnetic field. This material shows a quantum phase transition from a Néel ordered phase at zero field to a longitudinal incommensurate spin density wave at a critical magnetic field of 3.8 T. Concomitantly, the excitation gap almost closes and a fundamental reconfiguration of the spin dynamics occurs. These experimental results are well described by the universal Tomonaga-Luttinger liquid theory developed for interacting spinless fermions in one dimension. We especially observe the rise of mainly longitudinal excitations, a hallmark of the unconventional low-field regime in Ising-like quantum antiferromagnetic chains

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Quentin Faure, Shintaro Takayoshi, Virginie Simonet, Beatrice Grenier, Martin Månsson, et al.. Tomonaga-Luttinger Liquid Spin Dynamics in the Quasi-One-Dimensional Ising-Like Antiferromagnet BaCo 2 V 2 O 8. Physical Review Letters, 2019, 123 (2), pp.027204. ⟨10.1103/PhysRevLett.123.027204⟩. ⟨hal-02394840⟩