Vincent Mourik (TUDelft)

“Majorana fermions in hybrid superconductor-semiconductor nanowire devices”

In condensed matter physics, Majorana fermions are theoretically proposed fermionic quasiparticles that are equal to their own antiparticle. Theoretically these quasiparticles have been investigated intensively for almost two decades which resulted in many exciting predictions, some of which are direct results from work done at Leiden University. The most important expectation is that Majorana fermions obey so called ‘non-abelian’ exchange statistics. This property could become very usefull in designing a robust quantum computer.

Contrary to the rather mature status of the theoretical developments, experimentally the field is only in its initial stage: experiments are currently focusing on assembling devices based on the right materials and establish the presence of Majorana fermions in such structures. My own research carried out at TU Delft focusses on one particular system that could potentially host Majorana fermions: a device based on InSb semiconducting nanowires combined with a s-wave superconductor, NbTiN. We have observed a promising feature in tunnel spectroscopy measurements that gives evidence for the presence of a Majorana fermion in our structure [1].

In my talk I will try to give an introduction and overview of the topic from an experimental perspective. Emphasis will be put on what are experimentally necessary conditions to observe the non-abelian exchange statistics of Majorana fermions and how our current experiments in Delft fit in this development towards giving proof of the ‘non-abelianess’ of Majorana fermions by performing braiding operations.

[1] V. Mourik, K. Zuo, S.M. Frolov, S.R Plissard, E.P.A.M. Bakkers, L.P. Kouwenhoven, Science Vol. 336 no. 6084 pp. 1003-1007, 2012.