Research Projects

Strongly-correlated compounds have allured the physics community for many decades to understand the rich variety of perplexing phenomena arising from the quantum many-body interactions of quasiparticles, includ- ing high-temperature superconductivity. Recent experimental findings of superconductivity in compounds with kagom ?e, Lieb and honeycomb lattices, in which strong correlation arising from dispersion-less flat bands coexists with non-trivial band topological properties, have revived the interest in such compounds. Primary candidates for the renewed interest in such strongly-correlated superconductors are AV3Sb5 (A=K, Rb, Cs). These kagom ?e metals exhibit electronic bands with a Z2 topological invariant near the Fermi energy, anomalous Hall effect, no signs of magnetism yet interestingly a chiral charge density wave order. The origin of the superconductivity and that of the charge density wave are still unknown. It is also not clear whether these two long-range orders compete or cooperate in this family of compounds. The non-trivial band topology and the chiral charge density wave may open a novel route to topological superconductivity, hosting the zero-energy Majorana bound states. Even in the presence of strong electronic correlations, there is a possibility to realize fractionalized topological quasiparticles such as parafermions. Therefore, these correlated superconductors provide an oppor- tunity to explore a plethora of important physical properties, and to test the laboratory realization of the elusive Majorana and parafermion quasiparticles, that are believed to be useful in decoherence-free quantum computing.