Effects of magnetic-field orientation and disorder on Majorana polarization in topological superconducting wires
V.V. Val’kov and S.V. Aksenov
L.V. Kirenskiy Institute of Physics, Siberian Branch of the Russian Academy of Sciences Krasnoyarsk 660036, Russia
Received December 6, 2016
The behavior of the Majorana polarization for the one-dimensional wire in topological superconduct-ing phase, previously introduced by D. Sticlet et al. [Phys. Rev. Lett. 108, 096802 (2012)], is investigated depending on the magnetic-field orientation. On the basis of the numerical calculations we show that in the case of the canted field this polarization on opposite ends of the wire may be different both in sign and in magnitude. Since the Majorana polarization on one end has different sign when the magnetic field changes the orientation from the transverse to the longitudinal one, there is a range of angles at which this value is significantly suppressed or equal to zero. Therefore, the Majorana polarization cannot always be considered as a local order parameter at an arbitrary angle of the magnetic field in the plane perpendicular to the effective Rashba field. It has been demonstrated that Anderson disorder doesn't lead to qualitatively new effects. At the same time, it causes the appearance of the additional areas with weak Majorana polarization at high magnetic fields.
PACS 73.21.Hb Quantum wires;
Key words: Majorana fermions, topological superconductivity, spin polarization.
Published online:: February 24, 2017
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