Monday, July 2, 2012

1206.7109 (Xiong-Jun Liu et al.)

Manipulating Majorana Fermions in Quantum Nanowires with Broken
Inversion Symmetry
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Xiong-Jun Liu, Alejandro M. Lobos
We predict that a Majorana quantum wire, driven into a trivial phase by tilting the external magnetic field as observed in experiment [V. Mourik et al., Science 336, 1003 (2012)], can be restored into the topological phase by applying a supercurrent in the proximate superconductor (SC). A tilted external magnetic field breaks spatial inversion symmetry and closes the superconducting gap in the wire when the tilt angle exceeds a critical value, leading to a topological phase transition. Interestingly, we show that a supercurrent applied in the SC is able to restore the Majorana end-states. Using Abelian bosonization, we further confirm this result in the presence of electron-electron interactions and show the analogy of this phenomenon to the commensurate-incommensurate transition driven by doping a one-dimensional Mott-insulator system. The present results have important applications in e.g., realizing the supercurrent assisted braiding (SAB) of Majorana fermions, which proves highly useful in topological quantum computation with realistic Majorana networks.
View original: http://arxiv.org/abs/1206.7109

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