Shot noise distinguishes Majorana fermions from vortices injected in the edge mode of a chiral p-wave superconductor

Abstract

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.

15 pages, 4 figures

References in corpus (5)

• Electrically detected interferometry of Majorana fermions in a topological insulator
• A note on the Full Counting Statistics of paired fermions
• Scattering theory of chiral Majorana fermion interferometry
• Half-integer charge injection by a Josephson junction without excess noise
• Wiedemann-Franz-type relation between shot noise and thermal conduction of Majorana surface states in a three-dimensional topological superconductor

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• Coulomb blockade of chiral Majorana and complex fermions far from equilibrium
• Current cross-correlation spectroscopy of Majorana bound states
• Theory of Berry Singularity Markers: Diagnosing Topological Phase Transitions via Lock-In Tomography