Probing Neutral Majorana Fermion Edge Modes with Charge Transport

Liang Fu, C. L. Kane

Physical Review Letters · 2009 · 569 citations · 24 references

DOIFull text

Open access

Concepts

TL;DR

The authors propose two experiments—a junction‑based probe and a novel interferometer—to detect Majorana fermion edge states and their Z2 phase on a topological insulator surface. They combine Majorana pairs into Dirac fermions on magnetic domain walls, use a superconducting junction point contact whose transmission is phase‑controlled, and propose a topological‑insulator‑based interferometer to measure neutral Majorana transport. The point‑contact transmission is tunable via the junction phase difference, and the scheme is feasible on Bi₂Se₃.

Abstract

We propose two experiments to probe the Majorana fermion edge states that occur at a junction between a superconductor and a magnet deposited on the surface of a topological insulator. Combining two Majorana fermions into a single Dirac fermion on a magnetic domain wall allows the neutral Majorana fermions to be probed with charge transport. We will discuss a novel interferometer for Majorana fermions, which probes their Z2 phase. This setup also allows the transmission of neutral Majorana fermions through a point contact to be measured. We introduce a point contact formed by a superconducting junction and show that its transmission can be controlled by the phase difference across the junction. We discuss the feasibility of these experiments using the recently discovered topological insulator Bi2Se3.

References

24