Neutron Interference Experiments and Quantum Measurement Theory

Complementarity, Measurement and Information in Interference Experiments

Different criteria (Shannon's entropy, Bayes' average cost, Dürr's normalized rms spread) have been introduced to measure the " which-way " information present in interference experiments where, due to non-orthogonality of the detector states, the path determination is incomplete. For each of these criteria, we determine the optimal measurement to be carried on the detectors, in order to read o...

Unavoidable losses in neutron quantum experiments

Quantum optics experiments contribute to a deeper understanding of quantum theory. Neutron phase-echo and spin rotation experiments have shown that, in all cases of an interaction, parasitic beams are produced which cannot be recombined with the original beam in an ideal way. This means that a complete reconstruction of the original state would, in principle, be impossible. Thus a kind of intri...

Quantum interference experiments with large molecules

Wave–particle duality is frequently the first topic students encounter in elementary quantum physics. Although this phenomenon has been demonstrated with photons, electrons, neutrons, and atoms, the dual quantum character of the famous double-slit experiment can be best explained with the largest and most classical objects, which are currently the fullerene molecules. The soccer-ball-shaped car...

Operational Quantum Theory; Measurement Theory

Neutron-multiwave-interference experiments with many resonance coils

Neutron-multiwave-interference phenomena based on Ramsey’s resonance method of ‘‘separated oscillating fields’’ are studied. A neutron passes through N successive resonant coils (\v052mnB0), which flip the neutron spin with a probability r smaller than 1. These coils are separated by path lengths L over which a homogeneous field B1 is present. Because the spin-flip probability r is smaller than...