https://doi.org/10.1140/epjb/e2014-50243-9
Regular Article
Majorana fermions in honeycomb lattices
1
Laboratoire de Physique des Solides, 91400
Orsay,
France
2
Institut de Physique Théorique, CEA/Saclay,
Orme des Merisiers,
91190
Gif-sur-Yvette Cedex,
France
a
e-mail: marine.guigou@gmail.com
Received: 10 April 2014
Received in final form: 23 June 2014
Published online: 8 December 2014
We study the formation of Majorana fermions in honeycomb-lattice structures in the presence of a Zeeman field, Rashba spin-orbit coupling, and in the proximity of an s-wave superconductor. We show that an exact mapping exists between an anisotropic hexagonal-lattice nanoribbon at k = 0 and a one-dimensional chain, for which the existence of Majorana fermions has been extensively discussed. Consequently we can find the conditions for the emergence of Majorana fermions in such a ribbon for particular values of the chemical potential such as the top or the bottom of the band, and the Van Hove singularities, and relate the existence of Majoranas to a band inversion in the bulk band structure. Moreover we find that similar situations arise in anisotropic lattices and we give some examples which show the formation of Majorana fermions in these structures.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2014
