1103.2770 (Jay D. Sau et al.)

Majorana resonances and how to avoid them in periodic topological
superconductor-nanowire structures    [PDF]

Jay D. Sau, Chien Hung Lin, Hoi-Yin Hui, S. Das Sarma

Semiconducting nanowires in proximity to superconductors are promising
experimental systems for Majorana fermions which may ultimately be used as
building blocks for topological quantum computers. A serious challenge in the
experimental realization of the Majorana fermion in these
semiconductor-superconductor nanowire structures is tuning the semiconductor
chemical potential in close proximity to the metallic superconductor. We show
that, presently realizable structures in experiments with tunable chemical
potential lead to Majorana resonances, which are interesting in their own
right, but do not manifest non-Abelian statistics. This poses a central
challenge to the field. We show how to overcome this challenge, thus resolving
a crucial barrier to the solid state realization of a topological system
containing the Majorana fermion. We propose a new topological superconducting
array structure where introducing the superconducting proximity effect from
adjacent nanowires generates Majorana fermions with non-Abelian statistics.

View original: http://arxiv.org/abs/1103.2770