2017/10/31 by Zheng Zhu, Itamar Kimchi, D. N. Sheng +1 · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.97.241110
published as Phys. Rev. B 97, 241110 (2018) · 8 pages, 8 figures
arxiv created 2018/06/21 · arxiv updated 2018/06/27
We investigate the non-Abelian topological chiral spin liquid phase in the two-dimensional (2D) Kitaev honeycomb model subject to a magnetic field. By combining density matrix renormalization group (DMRG) and exact diagonalization (ED) we study the energy spectra, entanglement, topological degeneracy, and expectation values of Wilson loop operators, allowing for robust characterization. While the ferromagnetic (FM) Kitaev spin liquid is already destroyed by a weak magnetic field with Zeeman energy H_*FM ≈ 0.02, the antiferromagnetic (AFM) spin liquid remains robust up to a magnetic field that is an order of magnitude larger, H_*AFM ≈ 0.2. Interestingly, for larger fields H_*AFM < H < H**AFM, an intermediate gapless phase is observed, before a second transition to the high-field partially-polarized paramagnet. We attribute this rich phase diagram, and the remarkable stability of the chiral topological phase in the AFM Kitaev model, to the interplay of strong spin-orbit coupling and frustration enhanced by the magnetic field. Our findings suggest relevance to recent experiments on RuCl3 under magnetic fields.