Correlation-driven metallic topology

Developments in the past decade have shaped the term topological quantum matter.In the solid state, much progress has been made on non- and weakly-interactingsystems and correlated insulators, but gapless topological phases governed bystrong correlations are a completely open challenge.

They are of great interestbecause a wealth of new quantum phases with new properties and functionalitiesare expected.The PI and her collaborators have recently discovered one such phase - theWeyl-Kondo semimetal - and brought to light its extreme topological responses aswell as the feasibility of genuine topology control by external parameters.

Thissets the stage for the present project.In CorMeTop new correlation-driven gapless topological phases shall bediscovered and design principles for such phases established.

New signatures ofthese phases shall be revealed and their potential for quantum devices assessed.To achieve these objectives, the versatile platform of heavy fermion compoundswill be used.

Four different design principles - symmetry, emergence, engineeredplatforms, and parameter tuning - will be followed, and a combination ofrecently established and entirely new experimental probes will be used.

Thebasis for these studies will be high-quality bulk single crystals and thin filmsgrown by molecular beam epitaxy.Among the questions to be addressed are: To which extent does symmetry dictatethe fate of topological states in the limit of strong correlations? What is theconnection between quantum criticality or other emergent phenomena, long-rangeentanglement, and topology?

Can entirely new platforms based on heavy fermionsystems stabilize robust and even braidable Majorana bound states? Whichtheoretical parameters control topology and how can one vary themexperimentally?

Which functionalities bear potential for quantum applications?We expect the project to establish an emerging field, and provide guidance to alarger community to boost progress.