Efficient Tomography of Non-Interacting Fermion States

There are two types of particles in the universe: bosons and fermions. Bosons include force carriers, such as photons and gluons, and fermions include matter particles like quarks and electrons. Each particle can be in a certain mode (e.g., a position or state). For a system of n particles, a configuration of the system is described by specifying how many particles are in each of m modes. Bosons are particles where multiple occupancy of a mode is allowed, whereas fermions are particles where multiple occupancy is forbidden; that is, two or more fermions cannot occupy the same mode at once (this is the Pauli exclusion principle).