In this seminar, I discuss the problem of creating Majorana
zero modes in a cold-atom system, which is naturally
number-conserving, and without assuming the presence of a
I begin by presenting a model of interacting fermions in a
two-leg ladder supporting zero-energy Majorana edge modes.
The model has a quasi-exactly solvable line for all possible
densities of fermions described by a topologically
non-trivial ground state wave-function which can be fully
In the second part of the seminar, I argue that all the
necessary ingredients for the appearance of Majorana zero
modes in number-conserving ladders are naturally present in
one-dimensional Ytterbium gases (and more generally in
earth-alkaline(-like) atomic gases), which are currently
studied in several state-of-the-art experiments. I support
the claim with extensive numerical simulations.
 Iemini, Mazza, Rossini, Fazio, and Diehl, Phys. Rev.
Lett. 115, 156402 (2015).
 Iemini, Mazza, Fallani, Zoller, Fazio, and Dalmonte,
Phys. Rev. Lett. 118, 200404 (2017).