1204.4212 (Leonid P. Rokhinson et al.)

Observation of the fractional ac Josephson effect: the signature of
Majorana particles    [PDF]

Leonid P. Rokhinson, Xinyu Liu, Jacek K. Furdyna

We report the observation of the fractional ac Josephson effect in hybrid semiconductor/superconductor InSb/Nb nanowire junctions, a hallmark of topological matter. When the junction is irradiated with rf frequency f at zero external magnetic field, quantized voltage steps (Shapiro steps) with a height \Delta V=hf/2e are observed, as is expected for conventional superconductor junctions where the supercurrent is carried by charge-2e Cooper pairs. At high fields the height of the first Shapiro step is doubled to hf/e. The supercurrent carried by charge-e quasiparticles is a unique signature of Majorana fermions, elusive particles predicted ca. 80 years ago.

View original: http://arxiv.org/abs/1204.4212