Tomonaga-Luttinger Liquid Spin Dynamics in the Quasi-One-Dimensional Ising-Like Antiferromagnet BaCo_{2}V_{2}O_{8}

Quentin Faure; Shintaro Takayoshi; Virginie Simonet; Béatrice Grenier; Martin Månsson; Jonathan S White; Gregory S Tucker; Christian Rüegg; Pascal Lejay; Thierry Giamarchi; Sylvain Petit

doi:10.1103/PhysRevLett.123.027204

Tomonaga-Luttinger Liquid Spin Dynamics in the Quasi-One-Dimensional Ising-Like Antiferromagnet BaCo_{2}V_{2}O_{8}

Phys Rev Lett. 2019 Jul 12;123(2):027204. doi: 10.1103/PhysRevLett.123.027204.

Authors

Quentin Faure^{1

2}, Shintaro Takayoshi^{3

4}, Virginie Simonet², Béatrice Grenier¹, Martin Månsson^{5

6}, Jonathan S White⁵, Gregory S Tucker^{5

7}, Christian Rüegg^{4

5

8}, Pascal Lejay², Thierry Giamarchi⁴, Sylvain Petit⁹

Affiliations

¹ Université Grenoble Alpes, CEA, IRIG, MEM, MED, F-38000 Grenoble, France.
² Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France.
³ Max Planck Institute for the Physics of Complex Systems, Dresden D-01307, Germany.
⁴ Department of Quantum Matter Physics, University of Geneva, Geneva CH-1211, Switzerland.
⁵ Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI CH-5232, Switzerland.
⁶ Department of Applied Physics, KTH Royal Institute of Technology, Kista, Stockholm SE-10044, Sweden.
⁷ Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland.
⁸ Neutrons and Muons Research Division, Paul Scherrer Institute, Villigen PSI CH-1211, Switzerland.
⁹ Laboratoire Léon Brillouin, CEA, CNRS, Université Paris-Saclay, CEA-Saclay, Gif-sur-Yvette F-91191, France.

PMID: 31386519
DOI: 10.1103/PhysRevLett.123.027204

Abstract

Combining inelastic neutron scattering and numerical simulations, we study the quasi-one-dimensional Ising anisotropic quantum antiferromagnet BaCo_{2}V_{2}O_{8} 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.