Fermion and boson pairs in beamsplitters and Mach–Zehnder interferometers

In this short topical review, we look at something typically considered trivial, but not given formally elsewhere—the behaviour of first multiple fermions, then multiple bosons, in a beamsplitter. Extending from this, we then describe the behaviour of multiple fermions and multiple bosons in Mach–Zehnder interferometers. We hope that by showing how to go from mathematically simple but unintuitive quantum field theory to a phenomenological description, this review will help both researchers and students build a stronger intuition for the behaviour of quantum particles.