Centre for Nanoscience
and Nanotechnology

  • CNRS
  • UPsud

PHYNANO Group

Next Seminar (online)

Progress in realizing topological superconductivity in planar Josephson junctions

Thursday June 4th 2020, 16h – Online
Invited speaker:
Javad Shabani

NYU

Recently the drive to understand and control the order parameter characterizing the collective state of electrons in quantum heterostructures has attracted great interest. New physical behavior can emerge that is absent in the isolated constituent materials. With regards to superconductivity this has opened a whole new area of investigation in the form of topological superconductivity. Topological superconductivity are expected to host exotic quasi-particle excitations including Majorana bound states which hold promise for fault-tolerant quantum computing. Recent theory predicts in superconductor-semiconductor devices, Majorana bound states can emerge and are accompanied by a topological phase transition. We show experimentally in epitaxial Al/InAs Josephson junctions a transition between trivial and topological superconductivity. We observe a minimum of the critical current at the topological transition, indicating a closing and reopening of the superconducting gap induced in InAs, with increasing magnetic field. By embedding the Josephson junction in a phase-sensitive loop geometry, we measure a π-jump in the superconducting phase across the junction when the system is driven through the topological transition. These findings reveal a versatile two-dimensional platform to explore topological superconductivity for quantum computing.

Upcoming seminars

  • David Goldhaber-Gordon - 15/06/2020

  • Preden Roulleau (SPEC) - TBA

  • Zaki Leghtas (LPENS) - TBA

  • Kamran Behnia (ESPCI) - TBA

  • Matthieu Delbecq (LPENS) - TBA

  • Hugues Pothier (SPEC) - TBA

  • Christophe Brun (INSP) - TBA

 

 

Past seminars 2020

  • Olivier Maillet (Aalto)

  • Mitali Banerjee (EPFL)

  • Anais Dreau (L2C) 

  • Klaus Ensslin (ETH- Zurich) 

  • Xavier Waintal (CEA- Grenoble) 

  • Gwendal Feve (LPENS) 

  • Shuoying Yang (MPI-Halle) 

  • Yann Gallais (MPQ) 

  • Carles Altimiras (CEA - Saclay)

  • Alexandra Palacio- Morales ( LPS) 

  • Everton Arrighi (Neel Institute)