Sequential Measurements in Quantum Mechanics

Costantino Budroni, Tobias Moroder, Matthias Kleinmann +1 more

Sequential measurements on a single particle play an important role in fundamental tests of quantum mechanics. We provide a general method to analyze temporal quantum correlations, which allows us to compute the maximal correlations for sequential measurements in quantum mechanics. As an application, we present the full characterization of temporal correlations in the simplest Leggett-Garg scenario and in the sequential measurement scenario associated with the most fundamental proof of the Kochen-Specker theorem.

Jennifer R. Glick, Christoph Adami

Gianni Cassinelli, Ernesto De Vito, PEKKA J. LAHTI +1 more

A rule is proposed to calculate the geometric phase accumulating in the course of a sequential measurement process. This rule is based on the assumptions of a sequential conditioning and a geodesic hypothesis. The dependence of this phase on the type of the applied measurements is explicated.

Bartel Leenert van der Waerden

Paul Busch, Gianni Cassinelli, PEKKA J. LAHTI

Marco Genovese, Salvatore Virzì, Alessio Avella +11 more

Weak value measurements have been a real breakthrough in the quantum measurement framework. In particular, quantum measurements may take advantage by anomalous weak values, i.e. values out of the eigenvalues spectrum of the measured observable, both for implementing new measurement techniques and studying Quantum Mechanics foundations. In this report we show three experiments with single photons presenting anomalous weak values: the first one tests the incompatibility between quantum mechanics and noncontextual hidden variables theories, the second one is the first realization of a sequential weak value evaluation of two incompatible observables on the same photon, and the last one shows how sequential weak values can be used to test Leggett-Garg inequalities extended to multiple-measurements scenarios.