The study titled "Deconfinement of Majorana Vortex Modes Produces a Superconducting Landau Level", by Sabanci University Engineering and Natural Sciences Faculty Member İnanç Adagideli, is featured on the June 2021 cover of the Physical Review Letters journal.
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Majoranas resist being blown away
Majoranas in condensed matter are collectively moving particles (electrons in this case) that behave as if they are single particles that are their own antiparticles. Once found, they could be used to build noise resistant quantum computers. What makes them interesting, namely being their own antiparticle, having no electric charge, no spin, and zero energy, also makes them very difficult to detect.
What also makes them very hard to detect is that they are usually hiding in hard to reach places: for instance they were predicted to exist in a hybrid structure in which a topological insulator is put on a superconductor. A while ago Liang Fu and Charles Kane predicted that Majoranas will appear when such a heterostructure is placed in a magnetic field. Superconductors push out magnetic fields; the magnetic field lines pierce the superconducting material through tiny regions. In these tiny regions, called the vortex cores, superconductivity vanishes, allowing the magnetic field through. Majoranas will hide in these cores.
Sabancı University and the Leiden University theorists decided to further analyze Fu-Kane materials, and asked if Majoranas can be eased out of their "hiding hole" by blowing a supercurrent through them. It turns out this indeed causes Majoranas to pop out of their homes at the vortex cores and meet each other. Majoranas, being their own antiparticles, can annihilate each other. But surprisingly, according to the paper published this week in Physical Review Letters, they resist annihilation. The cover of Physical Review Letters this week features the signature intensity profile of this state where Majoranas are deconfined.