Dynamical Structure Factor of the anisotropic spin-1/2 Heisenberg chain in a transverse magnetic field

Oz Bonfim, J. Florencio

F. Capraro, Claudius Gros

Hamed Rezania

Jean-Sébastien Caux, Fabian H. L. Eßler, U. Löw

We consider the anisotropic Heisenberg spin-1/2 chain in a transverse magnetic field at zero temperature. We first determine all components of the dynamical structure factor by combining exact results with a mean-field approximation recently proposed by Dmitriev et al. [JETP 95, 538 (2002)]. We then turn to the small anisotropy limit, in which we use field theory methods to obtain exact results. We discuss the relevance of our results to neutron scattering experiments on the one-dimensional Heisenberg chain compound ${\mathrm{Cs}}_{2}{\mathrm{CoCl}}_{4}.$

Rodrigo G. Pereira, Jesko Sirker, Jean-Sébastien Caux +4 more

Igor Kuzmenko, Fabian H. L. Eßler

We consider the easy-plane anisotropic spin-$\frac{1}{2}$ Heisenberg chain in combined uniform longitudinal and transverse staggered magnetic fields. The low-energy limit of his model is described by the sine-Gordon quantum field theory. Using methods of integrable quantum field theory we determine the various components of the dynamical structure factor. To do so, we derive explicit expressions for all matrix elements of the low-energy projections of the spin operators involving at most two particles. We discuss applications of our results to experiments on one-dimensional quantum magnets.