Neutron scattering study on K2Co2TeO6, a Kitaev interactions candidate

Since the quantum spin liquid (QSL) state may reveal the microscopic origin of high-transition-temperature superconductivity and serve as a novel platform to perform quantum computation, the experimental realization of a QSL is a long-sought goal in condensed matter physics. One of the most promising candidates for the QSL phase is the Kitaev model based on anisotropic interactions among spin-1/2 particles on a honeycomb lattice. Recently, our collaborators have successfully synthesized a new compound, K2Co2TeO6 in the P63/mcm space group (No. 193) with lattice constants a = 5.2099(4) Å and c = 12.6214(17) Å, in which Co2+ ions form a honeycomb sublattice in each Co-Te layer. This experiment aims to determine the exchange couplings in the Hamiltonian by fitting the magnon spectra and determine if the exchange couplings are consistent with Kitaev interactions. We will fit the spin wave in K2Co2TeO6 and try to extract the exchange couplings, which will help to determine the magnitude of Kitaev interaction in our future field experiments. It will also help unveil the mechanism of the complex magnetism in K2Co2TeO6.