The realization of a generalized spin measurement

Abstract

A generalized spin measurement, as opposed to a projective measurement, can produce interesting effects such as the weak Zeno effect (Cresser et al 2006 Opt. Commun. 264 352). In the weak limit a generalized spin measurement can also lead to surprising weak values (Aharonov et al 1988 Phys. Rev. Lett. 60 1351). In this paper we show explicitly how a generalized spin measurement can be realized physically by entangling the spin to be measured with a pointer spin. Adjustment of the interaction time allows any amount of generalization to be achieved, ranging from a projective measurement to the limit of a very weak measurement.