Optical conductivity of the Majorana mode at the s- and d-wave topological superconductor edge

Abstract

The Majorana fermion offers fascinating possibilities such as non-Abelian statistics and non-local robust qubits, and hunting it is one of the most important topics in current condensed matter physics. Most of the efforts have been focused on the Majorana bound state at zero energy in terms of scanning tunneling spectroscopy searching for the quantized conductance. On the other hand, a chiral Majorana edge channel appears at the surface of a three-dimensional topological insulator when engineering an interface between proximity-induced superconductivity and ferromagnetism. Recent advances in microwave spectroscopy of topological edge states open a new avenue for observing signatures of such Majorana edge states through the local optical conductivity. As a guide to future experiments, we show how the local optical conductivity and density of states present distinct qualitative features depending on the symmetry of the superconductivity, that can be tuned via the magnetization and temperature. In particular, the presence of the Majorana edge state leads to a characteristic non-monotonic temperature dependence achieved by tuning the magnetization.

Main text: 9 pages, 5 figures. Supplemental Information: 4 pages, 3 figures

References in corpus (12)

• Non-Abelian Anyons and Topological Quantum Computation
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Electrically detected interferometry of Majorana fermions in a topological insulator
• Proximity-induced high-temperature superconductivity in topological insulators Bi2Se3 and Bi2Te3
• Observation of a Majorana zero mode in a topologically protected edge channel
• Theory of Majorana zero modes in unconventional superconductors
• Induced superconductivity in the three-dimensional topological insulator HgTe
• Optical Responses of Chiral Majorana Edge States in Two-Dimensional Topological Superconductors
• Local Raman Spectroscopy of Chiral Majorana Edge Modes in Kitaev Spin Liquids and Topological Superconductors