We investigate two holes in the $t_{2g}$ levels of a square-lattice Mott insulator with strong spin-orbit coupling. Exact diagonalization spin-orbital model valid at onsite interactions, but arbitrary coupling and crystal field is complemented by an effective triplon (valid for coupling) semiclassical variant model. provide magnetic phase diagram depending on coupling, which largely agrees quan...

The concept of free fermion topology has been generalized to $d$-dimensional phases that exhibit $(d\ensuremath{-}n)$-dimensional boundary modes, such as zero-dimensional (0D) corner excitations. Motivated by recent extensions these ideas magnetic systems, we consider 2D quantum paramagnets formed interacting spin dimers with dispersive triplet We propose two examples dimer models, where the sp...

We demonstrate that low-lying triplon excitations in a bilayer Heisenberg antiferromagnet provide promising avenue to realize magnetic analogs of twisted superfluid and supersolid phases were recently reported for two-component ultracold atomic condensate an optical lattice. Using cluster Gutzwiller mean-field theory, we establish Dzyaloshinskii-Moriya interactions (DMI), are common many quantu...

We propose that Weyl triplons are expected to appear in the low energy magnetic excitations canonical Shastry-Sutherland compound, \ce{SrCu2(BO3)2}, a quasi-2D quantum magnet. Our results show when minimal, realistic inter-layer coupling is added well-established microscopic model describing excitation spectrum of individual layers, Dirac points zero-field triplon 2D split into two pairs along ...

The search for elementary excitations with fractional quantum numbers is a central challenge in modern condensed-matter physics. It has long been speculated that two-dimensional frustratedmagnets might support quantum disordered states with neutral spin-1/2 excitations known as spinons. Despite decades of search, however, no clear experimental examples have been found. We explore the possibilit...