2018/05/31 by Ciarán Hickey, Simon Trebst · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1038/s41467-019-08459-9
published as Nature Communications 10, 530 (2019) · 9 pages, 9 figures, Supplemental Material (4 pages, 4 figures). Final published version
arxiv created 2019/02/06 · arxiv updated 2019/02/07
In the field of quantum magnetism, the exactly solvable Kitaev honeycomb model serves as a paradigm for the fractionalization of spin degrees of freedom and the formation of ℤ2 quantum spin liquids. An intense experimental search has led to the discovery of a number of spin-orbit entangled Mott insulators that realize its characteristic bond-directional interactions and, in the presence of magnetic fields, exhibit no indications of long-range order. Here, we map out the complete phase diagram of the Kitaev model in tilted magnetic fields and report the emergence of a distinct gapless quantum spin liquid at intermediate field strengths. Analyzing a number of static, dynamical, and finite temperature quantities using numerical exact diagonalization techniques, we find strong evidence that this phase exhibits gapless fermions coupled to a massless U(1) gauge field. We discuss its stability in the presence of perturbations that naturally arise in spin-orbit entangled candidate materials.