Wydarzenia w AGH

Wykład zatytułowany Topological superconductivity and strong electronic correlations in moiré transition metal dichalcogenide bilayers wygłosi dr hab. inż. Michał Zegrodnik, prof. AGH (Akademickie Centrum Materiałów i Nanotechnologii AGH).

Udział

• stacjonarny: ACMiN (ul. Kawiory 30, bud. D-16, sala 1.02A)
• zdalny: platforma MS Teams (link)

Streszczenie

In recent years the twisted van der Waals heterostructures have gathered a significant amount of interest since they provide access to a variety of physical phenomena which are: unconventional forms of superconductivity, exotic magnetic properties, Mott physics as well as topological features. In those systems the spatial moiré potential modifies the electronic structure resulting in isolated narrow bands for certain twist angles. This in turn leads to an enhanced role of electron-electron interactions. During the talk I will focus on the transition metal dichalcogenide (TMD) based moiré structures which are characterized by a significant spin-orbit coupling. I will review selected experimental results for this group of systems and relate them with our theoretical calculations. In particular I will present the reconstruction of the two superconducting domes residing on both sides of the Mott insulating state on the phase diagram of the WSe2 homobilayer. According to our calculations the paired state is of highly exotic type characterized by a mixed singlet-triplet symmetry of the gap. Moreover the superconductivity has non-trivial topology with the non-zero value of the Chern number that can be tuned by the experimentally controllable parameter which is the displacement field. Additionally, I will analyze the appearance of the magnetically and charge ordered states. Our results show that the TMD moiré systems are promising candidates for highly tunable materials that can serve as a testing ground for understanding the interplay between strong electronic correlations, topology and various types of symmetry broken states.