Figure 2: Properties of a circular Shiba chain and a σx gate.
From: Manipulating Majorana zero modes on atomic rings with an external magnetic field
(a) For appropriate external magnetic field strength |B|, the circular magnetic chain (L=600 in this example) on a thin-film superconductor hosts four Majorana bound states (MBS) that can be measured as zero-bias anomalies with an STM tip. (b) Changing the orientation of B moves the MBS along the circle. (Black are trivial, white are topological sectors of the chain.) (c) Changing the magnitude of B controls their distance and allows to create and fuse them pairwise. (d) Two overlapping elliptic chains can be used as a σx gate that is operated by a 2π rotation of the angle 
of B in the 1–2 plane. Shown are the world lines of the MBS during the braid. Observe that the orange MBS braids around the red, green and blue MBS, while the green MBS braids around the blue and orange MBS only.
