Path detection and interference tradeoff in the double-slit experiment

Manpreet Kaur, Mandip Singh

Double-double-slit thought experiment provides profound insight on interference of quantum entangled particles. This paper presents a detailed experimental realisation of quantum double-double-slit thought experiment with momentum entangled photons and theoretical analysis of the experiment. Experiment is configured in such a way that photons are path entangled and each photon can reveal the which-slit path information of the other photon. As a consequence, single photon interference is suppressed. However, two-photon interference pattern appears if locations of detection of photons are correlated without revealing the which-slit path information. It is also shown experimentally and theoretically that two-photon quantum interference disappears when the which-slit path of a photon in the double-double-slit is detected.

Mohammad Bahrami, Afshin Shafiee

Jayaram AS

The double-slit experiment is one of the most important demonstrations of interference and hasplayed a central role in understanding wave behaviour and measurement in physics. In quantummechanical discussions, the availability of which-path information is associated with changes ininterference behaviour. This paper presents a double-slit thought experiment using microwave electromagnetic waves to examine the relationship between electromagnetic energy distribution andwhich-path information.Microwave double-slit experiments have demonstrated interference patterns by measuring electromagnetic intensity using antennas. In the present thought experiment, the same electromagneticwave arrangement is considered with different measurement approaches: localized detection of electromagnetic interactions and measurement of electromagnetic energy distribution at the two slitlocations.The central question addressed is whether electromagnetic energy detection at both slits providesinformation related to which-path information. The purpose of this work is to examine how differentforms of measurement information may be interpreted together.

Barry Kenneth Fleagle

Frederick W. Strauch

This paper considers a theoretical model of the double-slit experiment with electrons whose paths are monitored. This monitoring, inspired by a recent text by Maudlin, is performed by the Coulomb scattering of the electron by a proton. A simple quantum mechanical calculation is presented, inspired in part by a recent experimental demonstration of this famous thought experiment. The results illustrate the relationship between entanglement and the loss of coherence in the interference pattern. The tradeoff between the visibility of interference and the information gained by measurement is also explored. This calculation can provide advanced undergraduates insight into decoherence, entanglement, and quantum information.

Siddhant Das, Dirk-André Deckert, Leopold Kellers +2 more