SciPost Phys. 9, 080 (2020) ·
published 23 November 2020
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· pdf
The chiral edge modes of a topological superconductor support two types of
excitations: fermionic quasiparticles known as Majorana fermions and
$\pi$-phase domain walls known as edge vortices. Edge vortices are injected
pairwise into counter-propagating edge modes by a flux bias or voltage bias
applied to a Josephson junction. An unpaired edge mode carries zero electrical
current on average, but there are time-dependent current fluctuations. We
calculate the shot noise power produced by a sequence of edge vortices and find
that it increases logarithmically with their spacing - even if the spacing is
much larger than the core size so the vortices do not overlap. This nonlocality
produces an anomalous V log V increase of the shot noise in a voltage-biased
geometry, which serves as a distinguishing feature in comparison with the
linear-in-V Majorana fermion shot noise.
