Magnetism, Berry-curvature engineering and topology in chalcogenide superlattices and heterostructures

Developing novel platforms for electronic devices based on topological materials

Mission of the project

Topological phases are a fascinating field of research because their unconventional features, such as robust surface states, quantized physical observables, and exotic quasiparticles, not only challenge our fundamental understanding of matter but also have potential applications in electronics, spintronics, and quantum computing. In this project , we explore superlattices and heterostructures in chalcogenide materials and other relevant material systems, such as graphene, as a platform for novel electronic devices. In particular, we numerically study materials made up of single atomic layers or chains. By making use of the underlying geometric, topological, and magnetic properties of the electronic states, this research paves the way to more energy-efficient electronic devices and progress in spintronics. 

 

Robustness of flat-band superconductivity

We show that superconductivity decays universally in the presence of impurities. Most importantly, we find that a flat-band superconductor is as resilient to impurities as a conventional one. 

HgTe superlattices for 3D flat bands

We show that HgTe/CdTe superlattices realize nodal lines, which could host 3D flat bands without additional doping. We also find that HgTe/HgSe superlattices feature a rich topological phase diagram as a function of strain and pressure. 

Axion insulator in HgTe superlattices

We find that HgTe/MnTe superlattices realize the elusive axion insulator and other magnetic topological phases.

Transport in twisted bilayer graphene

We find a correspondence between electrical conductance and van-Hove singularities in the flat bands of twisted bilayer graphene. Our results suggest that this material could be used in high-frequency device applications and sensitive detectors


Topology of chalcogen chains

We find that tellurium and selenium realize elemental crystalline topological insulator formed by helical chains on a 2D array.  


Blog: Matter Meets Topology

A popular-science blog about the basic concepts of condensed matter physics