Effect of disorder in Kitaev materials*

Recent years have seen remarkable progress in identifying candidate materials that can realize Kitaev quantum spin liquid [1]. In particular, a significant experimental and theoretical effort has been devoted to the study of magnetic properties of 4d and 5d systems, such as iridates and ruthenates, in which the interplay of strong spin-orbit coupling and electronic correlations gives rise to highly anisotropic and spatially dependent Ising-like interactions between effective moments J=1/2. Many of these materials show the presence of various forms of disorder, such as site disorder (magnetic or non-magnetic impurities), bond disorder and layer stacking faults. This is why these systems offer a remarkable playground for new phenomena that can be realized as a cooperative manifestation of disordered topological condensed matter systems. Recently we argued [2] that a minimal model of a bond disordered Kitaev quantum spin liquid can account for most of the salient experimental findings in H3LiIr2O6 [3]. However, other implications of disorder might be crucial to account for all observations in this material. Here we discuss how include vacancies in this consideration and consider combined effect of bond disorder and vacances at finite temperature properties of the Kitaev quantum spin liquid.

[1] A. Kitaev, Ann. Phys. 321, 2 (2006).
[2] J. Knolle, R. Moessner, and N. B. Perkins, Phys. Rev. Lett. 122, 047202 (2019).
[3] K. Kitagawa, T. Takayama, Y. Matsumoto, A. Kato, R. Takano,Y. Kishimoto, S. Bette, R. Dinnebier, G. Jackeli, and H. Takagi, Nature 554, 341 (2018).