From transistors to Majorana fermions: a brief history of the physics of interfaces

by Enrico Rossi (Department of Physics, William and Mary)

Friday 28 Aug 2015, 15:30 → 16:30 Europe/Stockholm

NORDITA East Seminar Room

Over the past 50 years the ability to create interfaces with increasing control has allowed the discovery of phenomena of extraordinary fundamental and technological interest. A turning point in the history of the physics of interfaces was the discovery in 1980 of the Quantum Hall effect. Such discovery made clear that the study of interfaces and heterostructures could unlock completely new fundamental physics. Another turning point was the realization in 2004 of graphene. This finding led to the discovery of topological insulators and showed that many new designer heterostructures could be created by stacking, in a controlled way, sheets of novel materials with unique electronic properties, such as graphene. Most recently compelling evidence has emerged of the presence of Majorana fermions in some of these heterostructures. In this talk I will give an overview of the main fundamental effects that have been discovered thanks to the availability of novel interfaces and heterostructures. The focus will be on the ideas and physical concepts underlying such effects. I will discuss how the discovery of the Quantum Hall effect required the introduction of topological invariants to classify many-body states and show how such theoretical innovation played a key role in the discovery of topological insulators, topological superconductors, and Majorana fermions in novel heterostructures.