Accueil > Agenda Scientifique

19 octobre 2017: 1 événement

séminaire

  • Proximity-induced superconductivity in single and double Majorana nanowires

    Jeudi 19 octobre 11:00-12:00 - Christopher Reeg - Basel

    Proximity-induced superconductivity in single and double Majorana nanowires

    Résumé : In this talk, we will discuss various aspects of the superconducting proximity effect as it pertains to realizing topological superconductivity in both one- and two-nanowire systems. As experimental setups have moved almost exclusively toward inducing superconductivity in nanowires using a thin ( 10 nm thickness) layer of Al which forms a very strong contact, we will first discuss the influence of the finite thickness of the superconductor on the proximity effect. We will show that due to the large level spacing in Al, a large tunneling energy is required in order to reach the strong-coupling limit observed experimentally. However, we also show that such strong coupling induces a large shift in the effective chemical potential of the nanowire which pushes the topological threshold to magnetic field strengths greatly exceeding the critical field of Al. Next, we will show that intrawire and interwire pairing interfere destructively with one another in a double-nanowire system, and that this destructive interference can be utilized to significantly reduce the magnetic field threshold required to reach the topological phase. We will also discuss how to engineer (effective) Kramers pairs of Majorana fermions in double nanowires when time-reversal symmetry is explicitly broken.

    Lieu : salle 208a, aîle sud LPS, bât 510

    En savoir plus : Proximity-induced superconductivity in single and double Majorana nanowires