Interferometry with correlated fermions

Abstract

It is known and has been demonstrated experimentally that the sensitivity of an optical interferometer can be increased by injecting squeezed light into the unused port of the interferometer. Here it is demonstrated that the sensitivity of a fermion interferometer can also be enhanced provided the fermions in the input state are suitably correlated. An SU(2) formalism is introduced which allows one to concentrate on those quantum numbers of the input state which are of relevance to interferometer performance.