Publications

2019
M. Trif and Simon, P., “Braiding of Majorana Fermions in a Cavity”, Phys. Rev. Lett., vol. 122, p. 236803, 2019. Website
G. C. Ménard, et al., “Yu-Shiba-Rusinov bound states versus topological edge states in Pb/Si(111)”, The European Physical Journal Special Topics, vol. 227, p. 2303–2313, 2019. WebsiteAbstract
There is presently a tremendous activity around the field of topological superconductivity and Majorana fermions. Among the many questions raised, it has become increasingly important to establish the topological or non-topological origin of features associated with Majorana fermions such as zero-bias peaks. Here, we compare in-gap features associated either with isolated magnetic impurities or with magnetic clusters strongly coupled to the atomically thin superconductor Pb/Si(111). We study this system by means of scanning tunneling microscopy and spectroscopy (STM/STS). We take advantage of the fact that the Pb/Si(111) monolayer can exist either in a crystal-ordered phase or in an incommensurate disordered phase to compare the observed spectroscopic features in both phases. This allows us to demonstrate that the strongly resolved in-gap states we found around the magnetic clusters in the disordered phase of Pb have a clear topological origin.
2018
M. Trif, Dmytruk, O., Bouchiat, H., Aguado, R., and Simon, P., “Dynamic current susceptibility as a probe of Majorana bound states in nanowire-based Josephson junctions”, PHYSICAL REVIEW B, vol. 97, p. 041415, 2018.Abstract
We theoretically study a Josephson junction based on a semiconducting nanowire subject to a time-dependent flux bias. We establish a general density-matrix approach for the dynamical response of the Majorana junction and calculate the resulting flux-dependent susceptibility using both microscopic and effective low-energy descriptions for the nanowire. We find that the diagonal component of the susceptibility, associated with the dynamics of the Majorana state populations, dominates over the standard Kubo contribution for a wide range of experimentally relevant parameters. The diagonal term, explored, in this Rapid Communication, in the context of Majorana physics, allows probing accurately the presence of Majorana bound states in the junction.