Séminaire de groupe
Majorana and Andreev bound states in topological wires in the proximity of superconductors 
Denis Chevallier 
LPS Orsay 
jeudi 07 mars 2013 , 10h25 
Salle de séminaire du groupe de Physique Statistique 
We study onedimensional topological SN and SNS long junctions obtained by placing a topological insulating nanowire in the proximity of either one or two SC finitesize leads. Using the Majorana Polarization order parameter we find that for a finitesize SN junction the ABS spectrum exhibits a zeroenergy extended state which carries a full Majorana fermion, while the ABS of long SNS junctions with a phase difference of pi transform into two zeroenergy states carrying two Majorana fermions with the same MP. We also study the effects of finite SC penetration depths in such junctions. Last but not least we analyze a more realistic model for the coupling between a superconducting substrate and a topological wire, the resulting proximity effect, and the role played by the Andreev bound states in the topological wire in such a setup. 
