| Description |
Strong electron correlation effects are responsible for a number of interesting phenomena such as the fractional quantum Hall effect, Kondo effect, high-Tc superconductivity and spin-liquid behaviour. The Kitaev model - describing a strongly-correlated system of spin-1/2 particles on a honeycomb lattice with a highly direction-dependent interparticle interaction - has become one of the most actively studied strongly correlated electron systems in recent times. This model is integrable, and its ground state is a gapless quantum spin-liquid over a wide range of parameters. The elementary excitations in this spin-liquid phase consist of free Majorana fermions and Z2 vortices. I will discuss a number of impurity properties in the spin-liquid phase of the Kitaev model. These include an unusual Kondo effect and an RKKY interaction mediated by spinons, as well as the possibility of creating non-Abelian anyons by simply removing sites in the Kitaev model.
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