Perturbed Kitaev model: excitation spectrum and long-ranged spin correlations

التفاصيل البيبلوغرافية
العنوان: Perturbed Kitaev model: excitation spectrum and long-ranged spin correlations
المؤلفون: Lunkin, A. V., Tikhonov, K. S., Feigel'man, M. V.
المصدر: Journal of Physics and Chemistry of Solids 128 (2019), 130-137
سنة النشر: 2017
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Strongly Correlated Electrons
الوصف: We developed general approach to the calculation of power-law infrared asymptotics of spin-spin correlation functions in the Kitaev honeycomb model with different types of perturbations. We have shown that in order to find these correlation functions, one can perform averaging of some bilinear forms composed out of free Majorana fermions, and we presented the method for explicit calculation of these fermionic densities. We demonstrated how to derive an effective Hamiltonian for the Majorana fermions, including the effects of perturbations. For specific application of the general theory, we have studied the effect of the Dzyaloshinskii-Moriya anisotropic spin-spin interaction; we demonstrated that it leads, already in the second order over its relative magnitude $D/K$, to a power-law spin correlation functions, and calculated dynamical spin structure factor of the system. We have shown that an external magnetic field $h$ in presence of the DM interaction, opens a gap in the excitation spectrum of magnitude $\Delta \propto D h$.
Comment: 12 pages, 3 figures
نوع الوثيقة: Working Paper
DOI: 10.1016/j.jpcs.2017.11.009
URL الوصول: http://arxiv.org/abs/1710.04138
رقم الأكسشن: edsarx.1710.04138
قاعدة البيانات: arXiv
الوصف
DOI:10.1016/j.jpcs.2017.11.009