A new piece towards topological quantum computer


Each fermion has an antiparticle of opposite electric charge with which it annihilates. But this is not the case for Majorana fermions, which have no charge and are their own antiparticle.

Topological quantum computing is not the most advanced technology, but still quite promising. Indeed, Majorana fermions are ideal candidate for a qubit, because they are very weakly coupled to their environment and they benefit from a very high fidelity rate (quantum operations, measurements) and a very long coherence time. Nevertheless, experimental creation of Majorana fermions is very challenging and their observation can only be done indirectly.

In this theoretical study, published in Physical Review Letters, Rui-Xing Zhang and Prof. S. Das Sarma propose that a quasi-2D thin films of an iron-based superconducting material – FeSCs – would be a high temperature platform for gate-controlled helical topological superconductivity, giving rise to Majorana modes without the need for external proximity effect. In this case, Majorana modes are simply controlled by a magnetic field, which paves the way for the realisation of a topological quantum computer.