Ramanjit Sohal

The concept of topological order, which features long-range quantum entanglement in many-body systems, has been an important and active field in both condensed-matter physics and quantum information science. The state-of-the-art platforms designed for quantum computation have shown great ability and potential in preparing topological order. Notably, these devices are inherently open quantum systems coupled to the environment, resulting in mixed (instead of pure) quantum states.

No physical system is perfectly isolated from its environment. The consequence of coupling to the environment is decoherence—in which the system is inevitably brought to a (classical) probability distribution of quantum states, also known as a mixed state. Although quantum phases of matter have been well explored for isolated systems, our understanding of phases in the presence of decoherence is still under development.

Abstract Recent studies have demonstrated that measures of tripartite entanglement can probe data characterizing topologically ordered phases to which bipartite entanglement is insensitive. Motivated by these observations, we compute the reflected entropy and logarithmic negativity, a mixed-state entanglement measure, in tripartitions of bosonic topological orders using the anyon diagrammatic formalism. We consider tripartitions in which three subregions meet at trijunctions and tetrajunctions.