Perturbing Kitaev honeycomb magnets with staggered magnetic fields: A first-principle and exact-diagonalization study

Over the past decade, the response of Kitaev honeycomb magnets to external magnetic fields has cemented itself as a topic of tremendous interest. Besides providing fertile ground for the theoretical discovery of exotic phases of matter, including different quantum spin liquids and unconvetional forms of magnetic order, it has underpinned continued experimental efforts to observe related phenomena in Kitaev materials. The most prominent example among the latter is arguably α-RuCl₃, for which a uniform magnetic field can be used to suppress the zigzag-ordered ground state and give rise to an elusive regime whose thermal transport properties have been interpreted as signatures of Majorana fermions and topological magnons. In this talk, we will explore the prospect of generating novel phases of matter by subjecting Kitaev magnets to staggered external fields. Our results are divided in two parts. First, motivated by the approximate lattice matching of α-RuCl₃ and MnPS₃ monolayers, we employed density functional theory simulations to estimate the magnitude of the alternating field that the Néel-type order realized in MnPS₃ can generate on a neighboring α-RuCl₃ layer. Second, we used exact diagonalization to map out the zero-temperature phase diagram of an extended Kitaev model in a staggered field and characterize the various phases realized within it.