Condensed Matter Seminar: Macroscopic entanglement in strongly correlated superconductors

Abstract:

The inherent challenges of strongly correlated superconductors, such as heavy fermion materials, cuprates, pnictides and potentially twisted bilayer graphene, are intimately linked to macroscopic patterns of entanglement -- a topic of prime importance in the era of quantum information. I will concentrate on iron based superconductivity and review selected experimental observations and theoretical scenarios. Motivated by this introduction, I will discuss a novel mechanism for superconductivity employing a heuristic triplet resonating valence bond wave function. In this scenario, superconductivity emerges from a metallized spin liquid and thus from conduction electrons in the background of a gauge theory. This poses a formidable theoretical question on its own which I address at the level of tractable abstract toy models. In particular, I present results on the soluble limit and deconfinement-confinement phase transition in Kitaev's toric code supplemented with fermions. The presented results not only pave the way towards a better understanding of strongly correlated superconductors, but also illustrate the anticipated common ground of materials science and quantum information theory.

Event Organizer: Dr. Moshe Ben Shalom