InSb Nanowire Rail Tracks for Majoranas
Résumé
A quantum computer has computational power beyond that of conventional computers. Current technologies to fabricate quantum bits all suffer from decoherence, which destroys the quantum state and information is lost. The promise of topological quantum computation is that the quantum state is protected by the topology, and long coherence times can be expected [1]. The information is carried by quasi particles, which are called Majorana fermions.
Recently, the first signatures of Majorana fermions have been observed in one-dimensional InSb nanowires [2]. In order to demonstrate and exploit their non-Abelian statistics, the position of the Majorana states need to be interchanged [3]. This is not possible in a one-dimensional wire, since when two Majorana’s meet, they will be annihilated. Therefore more complex systems are needed.
Here, we discuss different approaches to fabricate branched InSb nanowire structures [4]. Important is that the junction is of high crystalline quality. We discuss routes to increase the yield of single crystalline tracks. Electrical contacts have been fabricated on all branches of the InSb nanowire crosses and low-temperature electrical measurements will be discussed. Hall effect measurements at low temperature prove the high quality of these new structures.
[1] S. Frolov et al. MRS Bulletin 2013, 38, 809.
[2] V. Mourik et al. Science 2012, 336, 1003
[3] J. Alicea et al. Nature Physics 2011, 7, 412
[4] S.R. Plissard et al. Nature Nanotechnology 2013. DOI: 10.1038/NNANO.2013.198