What distinguishes topologically trivial from non-trivial superfluids in interacting many-body systems with a conserved number of particles? What is the meaning and fate of Majorana zero-energy modes in interacting fermionic superfluids? These are questions that require a concrete operational answer if one seriously considers using these physical systems for quantum information processing purposes. Most of what we know about topological superfluids and Majorana bound states is based on a mean-field approximation, the Bogoliubov-de Gennes approach, that breaks particle-number conservation and, by construction, displays a particle-hole symmetry and thus a zero mode structure. I will attempt to answer the questions above from both basic physics principles, and concrete models perspectives. Finally, I will discuss a non-Abelian fermion parity interferometer that may provide the smoking gun for Majorana detection.
Coffee: 2:30 pm, 241 Compton