Electronic order and unconventional phase behavior in new classes of kagome metals

Kagome networks have long been predicted to host an interesting combination of features within their electronic band structures, ranging from localized flat bands to protected Dirac points to saddle points and their corresponding Van Hove singularities. Tuning band filling near these features is predicted to stabilize a wide array of electronic instabilities and presents an exciting means for realizing correlated electron states that potentially interplay with topologically nontrivial band features. Realizing these band structures in real materials is an enduring challenge, and one area of recent focus has been the ability to realize kagome metals with native band fillings close to the saddle points derived from their kagome band structures. Here I will present our recent work exploring a new class of materials of the form AV3Sb5 (A=K, Rb, Cs) that host vanadium-based kagome networks with their Fermi levels close to Van Hove fillings, providing a versatile material platform to test predictions of electronic order in this regime. I will present some of our recent experimental results exploring the charge density wave states and superconductivity that emerge in these compounds as well as the potential coupling between the two states. If time permits, comparisons with other recently discovered kagome metals and future directions will be presented.

Speaker: Stephen Wilson, Kent State University