1999/10/18 by Stefan Wessel, Stefan Weßel, Stephan Haas · 30 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Anisotropy #Ansatz #Antiferromagnetism #Bethe ansatz #Condensed matter physics #Ferromagnetism #Magnetic field #Magnon #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Spin (aerodynamics) #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.62.316
published in Physical review. B, Condensed matter 62(1), 316-323 (American Physical Society) · RevTex, 18 pages with 7 figures
arxiv created 1999/10/18 · openalex publication_date 2000/07/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A theoretical description is presented for low-temperature magnetic-field-induced three-dimensional (3D) ordering transitions in strongly anisotropic quantum antiferromagnets, consisting of weakly coupled antiferromagnetic spin-1/2 chains and ladders. First, effective continuum field theories are derived for the one-dimensional subsystems. Then the Luttinger parameters, which determine the low-temperature susceptibilities of the chains and ladders, are calculated from the Bethe ansatz solution for these effective models. The 3D ordering transition line is obtained using a random-phase approximation for the weak interchain (interladder) coupling. Finally, considering a Ginzburg criterion, the fluctuation corrections to this approach are shown to be small. The nature of the 3D ordered phase resembles a Bose condensate of integer-spin magnons. It is proposed that for systems with higher spin degrees of freedom, e.g., N-leg spin-1/2 ladders, multicomponent condensates can occur at high magnetic fields.