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Title: Reduced coherence in double-slit diffraction of neutrons

Abstract

In diffraction experiments with particle beams, several effects lead to a fringe visibility reduction of the interference pattern. We theoretically describe the intensity one can measure in a double-slit setup and compare the results with the experimental data obtained with cold neutrons. Our conclusion is that for cold neutrons the fringe visibility reduction is due not to decoherence, but to initial incoherence.

Authors:
 [1]; ;  [2]
  1. Mathematisches Institut, Eberhard-Karls-Universitaet, Auf der Morgenstelle 10, 72076 Tuebingen (Germany)
  2. Dipartimento di Fisica, Istituto Nazionale di Fisica Nucleare, Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy)
Publication Date:
OSTI Identifier:
20982609
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevA.75.055602; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COLD NEUTRONS; COMPARATIVE EVALUATIONS; INCOHERENT PRODUCTION; INTERFERENCE; NEUTRON DIFFRACTION; PARTICLE BEAMS; VISIBILITY

Citation Formats

Tumulka, R., Viale, A., and Zanghi, N. Reduced coherence in double-slit diffraction of neutrons. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.055602.
Tumulka, R., Viale, A., & Zanghi, N. Reduced coherence in double-slit diffraction of neutrons. United States. doi:10.1103/PHYSREVA.75.055602.
Tumulka, R., Viale, A., and Zanghi, N. Tue . "Reduced coherence in double-slit diffraction of neutrons". United States. doi:10.1103/PHYSREVA.75.055602.
@article{osti_20982609,
title = {Reduced coherence in double-slit diffraction of neutrons},
author = {Tumulka, R. and Viale, A. and Zanghi, N.},
abstractNote = {In diffraction experiments with particle beams, several effects lead to a fringe visibility reduction of the interference pattern. We theoretically describe the intensity one can measure in a double-slit setup and compare the results with the experimental data obtained with cold neutrons. Our conclusion is that for cold neutrons the fringe visibility reduction is due not to decoherence, but to initial incoherence.},
doi = {10.1103/PHYSREVA.75.055602},
journal = {Physical Review. A},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • The effects of incoherence and decoherence in a double-slit experiment are studied using both optical and quantum-phenomenological models. The results are compared with experimental data obtained with cold neutrons.
  • The authors report detailed experiments and comparison with first-principle theoretical calculation of the diffraction of cold neutrons (lambda4A2 nm) at single- and double-slit assemblies of dimensions in the 20--100 ..mu..m range. Their experimental results show all predicted features of the diffraction patterns in great detail. Particularly, their double-slit diffraction experiment is its most precise realization hitherto for matter waves.
  • A double-slit diffraction experiment is described for measuring pulse coherence time, pulse widths, and maximum power of laser radiation pulses. (AIP)
  • The wave nature of particles is rarely seen in nature. One reason is their very short de Broglie wavelengths in most situations. However, even with wavelengths close to the size of their surroundings, they couple to their environment, e.g. by gravity, Coulomb interaction, or thermal radiation. These couplings shift the phase of the waves, often in an uncontrolled way, hence yielding varying amounts of decoherence i.e. loss of phase integrity. Decoherence is thought to be a main cause of the transition from quantum to classical behavior. How much interaction is necessary and how big an environment is needed to inducemore » the onset of classical behavior? Here we show that a photoelectron and two protons form a minimum particle/slit system, and that a minimum environment can be no more than a single additional electron. We observe interference 'fringes' in the angular distribution of a single electron and the loss of fringe visibility caused by its Coulomb interaction with a second electron. While, at the same time, the correlated momenta of the entangled electron pair continue to exhibit quantum interference.« less