We consider a quantum dot coupled to a topological superconductor and two normal leads and study the transport properties of the system. Using a Keldysh path-integral approach, we study current fluctuations (shot noise) within the low-energy effective theory. We argue that the combination of the tunneling conductance and the shot noise through a quantum dot allows one to distinguish between the topological (Majorana) and nontopological (e.g., Kondo) origin of the zero-bias conduction peak. Specifically, we show that, while the tunneling conductance might exhibit a zero-bias anomaly due to Majorana or Kondo physics, the shot noise is qualitatively different in the presence of Majorana zero modes.

• Received 26 September 2014
• Revised 2 February 2015

DOI:https://doi.org/10.1103/PhysRevB.91.081405