Lecturer: Dr. Yuval Vinkler
Affiliation: Center for Complex Quantum Systems,
Freie University Berlin
Abstract:
Experimental evidence for Majorana bound
states largely relies on measurements of the
tunneling conductance. While the
conductance into a Majorana state is in
principle quantized to $2e^2/h$, observation
of this quantization has been elusive,
presumably due to temperature broadening in
the normal-metal lead. In this talk we will
describe a new suggestion to probe Majorana
bound states, using a superconducting lead,
whose gap strongly suppresses thermal
excitations. For a wide range of tunneling
strengths and temperatures, a Majorana state
is then signaled by symmetric conductance
peaks at $eV=\pm\Delta$ of a universal
height $G=(4-\pi)2e^2/h$. For a
superconducting scanning tunneling
microscope tip, Majorana states appear as
spatial conductance plateaus while the
conductance varies with the local
wavefunction for trivial Andreev bound
states. We will discuss effects of nonresonant
(bulk) Andreev reflections and quasiparticle
poisoning.