Charles M. Marcus

Spectroscopy of a Majorana Island

University of Copenhagen, Denmark

In this talk we use some well known tools of provided by Coulomb blockade of quantum dots to measure the enegy levels and lifetimes of subgap states, including Majorana states, in InAs semiconductor nanowires of various lengths proximitized by epitaxial Al and contacted with normal metal leads. Transport spectroscopy reveals subgap features with long poisoning times [1] that move and merge to zero energy in an applied magnetic field. Spectroscopy of small superconducting structues in this Copenhagen (NISIN) geometry is compared to related studies in the more familar Delft (NIS) geometry as well as related quantum dot (SINIS) devices in the literature.

Research is supported by Microsoft Station Q, the Danish National Research Foundation, Lundbeck Foundation, European Council and the US Department of Energy

[1] A. J. Higginbotham, et al. Parity lifetime of bound states in a proximitized semiconductor nanowire, arXiv:1501.05155 (2015)