2014/03/31 by Jianda Wu, Márton Kormos, Qimiao Si · 38 citations
Physics and Astronomy · #Condensed matter physics #Ising model #Neutron scattering #Physics #Physics of Superconductivity and Magnetism #Quantum many-body systems #Quantum mechanics #Relaxation (psychology) #Scattering #Statistical physics #Structure factor #Theoretical and Computational Physics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.113.247201
published in Physical Review Letters 113(24), 247201 (American Physical Society) · 5 pages 2 figures - Supplementary Material 11 pages
openalex publication_date 2014/12/09 · arxiv created 2014/12/10 · arxiv updated 2014/12/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A spectrum exhibiting E₈ symmetry is expected to arise when a small longitudinal field is introduced in the transverse-field Ising chain at its quantum critical point. Evidence for this spectrum has recently come from neutron scattering measurements in cobalt niobate, a quasi-one-dimensional Ising ferromagnet. Unlike its zero-temperature counterpart, the finite-temperature dynamics of the model has not yet been determined. We study the dynamical spin structure factor of the model at low frequencies and nonzero temperatures, using the form factor method. Its frequency dependence is singular, but differs from the diffusion form. The temperature dependence of the nuclear magnetic resonance (NMR) relaxation rate has an activated form, whose prefactor we also determine. We propose NMR experiments as a means to further test the applicability of the E₈ description for CoNb₂O₆.