Delayed-choice gedanken experiments and their realizations

Autor(en)

Xiao-song Ma, Johannes Kofler, Anton Zeilinger

Abstrakt

The wave-particle duality dates back to Einstein's explanation of the photoelectric effect through quanta of light and de Broglie's hypothesis of matter waves. Quantum mechanics uses an abstract description for the behavior of physical systems such as photons, electrons, or atoms. Whether quantum predictions for single systems in an interferometric experiment allow an intuitive understanding in terms of the particle or wave picture depends on the specific configuration which is being used. In principle, this leaves open the possibility that quantum systems always behave either definitely as a particle or definitely as a wave in every experimental run by a priori adapting to the specific experimental situation. This is precisely what is tried to be excluded by delayed-choice experiments, in which the observer chooses to reveal the particle or wave character of a quantum system-or even a continuous transformation between the two-at a late stage of the experiment. The history of delayed-choice gedanken experiments, which can be traced back to the early days of quantum mechanics, is reviewed. Their experimental realizations, in particular, Wheeler's delayed choice in interferometric setups as well as delayed-choice quantum erasure and entanglement swapping are discussed. The latter is particularly interesting, because it elevates the wave-particle duality of a single quantum system to an entanglement-separability duality of multiple systems.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Österreichische Akademie der Wissenschaften (ÖAW), Yale University, Nanjing University, Max-Planck-Institut für Quantenoptik

Journal

Reviews of Modern Physics

Band

88

Anzahl der Seiten

25

ISSN

0034-6861

DOI

https://doi.org/10.1103/RevModPhys.88.015005

Publikationsdatum

03-2016

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 103026 Quantenoptik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c9fca571-28fc-46b8-8529-6f32b2cdfdde