Description:

The experimental observation of Majorana states in topological superconductors represents a major breakthrough in realizing their applications in topological quantum computing and has stimulated the search for new possibilities to create and manipulate Majorana states at the nanoscale. Of particular interest have recently been magnetic-superconducting hybrid (MSH) structures in which islands of magnetic adatoms are placed on the surface of s-wave superconductors.

In this talk, I will provide several examples for quantum engineering of Majorana fermions in magnetic-superconducting hybrid structures. First, I will report the results of a theory-experiment collaboration demonstrating the ability to tune between a topological phase exhibiting chiral Majorana edge modes and a trivial phase in Fe-Re MSH structures. Second, I will demonstrate that in MSH systems, one can create and delete topological phases exhibiting chiral Majorana fermions by imprinting magnetic skyrmions. Similarly, it is possible to engineer chiral Majorana states of arbitrary shape through the creation of magnetic domain walls. Finally, I show that it is possible to continuously tune MSH systems between 2D and 1D topological phases, and thus to change the character of the associated Majorana modes.

Professor Dirk Morr, University of Illinois, Chicago

Host: Jim Sauls

Keywords: Physics, Astronomy, Condensed Matter