Thursday, March 01, 2012

Discovery of Majorana Fermions?

The big news so far coming out of the APS March Meeting going on right now is the result from the Leo Kouwenhoven group at Delft University. They reported on their latest experiment that, in some circles, shows compelling evidence for Majorana fermions.

Kouwenhoven’s apparatus is along the latter lines. In his group’s set-up, indium antimonide nanowires are connected to a circuit with a gold contact at one end and a slice of superconductor at the other, and then exposed to a moderately strong magnetic field. Measurements of the electrical conductance of the nanowires showed a peak at zero voltage that is consistent with the formation of a pair of Majorana particles, one at either end of the region of the nanowire in contact with the superconductor. As a sanity check, the group varied the orientation of the magnetic field and checked that the peak came and went as would be expected for Majorana fermions.
If this is true and verified, my earlier bet that Majorana fermions would probably be discovered in a condensed matter system first ahead of high energy physics experiments has come true! :)

In any case, this is an astounding experiment and an amazing accomplishment. I will eagerly anticipate reading the publication of this work.


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