Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Spectral modulation and squeezing at high-order neutron interferences

David L. Jacobson, S. A. Werner, H. Rauch

Published May 1, 1994• 82 citations
Publisher

Abstract

A striking spectral-modulation effect has been observed by means of a proper postselection procedure under conditions where the spatial shift of the wave trains greatly exceeds the coherence length of the neutron beams traversing an interferometer. It is shown that Schr\"odinger-cat-like states are created by the superposition of two coherent states generated in the interferometer. These entangled states exhibit, under certain circumstances, characteristic squeezing phenomena, indicating a highly nonclassical behavior. Analogies with optical experiments are discussed.

DOI
10.1103/physreva.49.3196

Related papers

Noise-induced dephasing in neutron interferometry

Georg Sulyok, Yuji Hasegawa, Jürgen Klepp +2 more

Decoherence phenomenona in a neutron interferometer are analyzed by simulation of the effects of an environment with magnetic noise fields. Basic calculations and experiments show the validity and limitations of this model system. In particular, loss and recovery of the interference pattern with controllable noise sources in both interferometer arms are discussed in detail. In addition, the decoherence behavior at high interference order, where Schr\"odinger-cat-like states exist in the interferometer, is investigated. While at low interference order a smearing of the interference pattern is observed, at high interference order a smearing of the modulated momentum distribution occurs.

Physical Review A•May 11, 2010•5 citations

Quantum Phenomena Tested By Neutron Interferometry

Helmut Rauch

Entanglement of two photons, or atoms is a complementary situation to a double slit situation of a single photon, neutron or atom. With neutrons single particle interference phenomena can be observed and the “entanglement of degrees of freedom”, i.e. contextuality can be verified. In this respect, neutrons are proper tools for testing quantum mechanics because they are massive, they couple to electromagnetic fields due to their magnetic moment and they are subject to all basic interactions, and they are sensitive to topological effects, as well. Related experiments will be discussed. Deterministic and stochastic partial absorption experiments can be described by Bell‐type inequalities. Recent neutron interferometry experiments based on postselection methods renewed the discussion about quantum nonlocality and the quantum measuring process. It has been shown that interference phenomena can be revived even when the overall interference pattern has lost its contrast. This indicates a persisting coupling in phase space even in cases of spatially separated Schrödinger cat‐like situations. These states are extremely fragile and sensitive against any kind of fluctuations and other decoherence processes. More complete quantum experiments also show that a complete retrieval of quantum states behind an interaction volume becomes impossible in principle.

AIP conference proceedings•Jan 1, 2005•1 citation

Wigner-function calculations for the coherent superposition of matter waves

P. B. Lerner, H. Rauch, M. Suda

Spectral filtering of the time-separated neutrons passing through an interferometer reconstitutes the interference pattern through the formation of a macroscopic superposition out of the neutron beams and produces squeezed states. In this paper we use matter-waves squeezed states produced in this way to manipulate the rate of expansion of the neutron wave packet. We demonstrate that these quantum states also have nontrivial correlations 〈\ensuremath{\Delta}k\ensuremath{\Delta}x〉. The Heisenberg relation for the spread of the wave packet holds even in this case and the reversal of the wave packet spreading is impossible. However, one can manipulate the rate of the wave packet expansion by changing the phase shift in one of the arms of a neutron interferometer.

Physical Review A•May 1, 1995•9 citations

Quantum Phenomena Studied by Neutron Interferometry

Helmut Rauch

Neutrons are proper tools for testing quantum mechanics because they are massive, they couple to electromagnetic fields due to their magnetic moment and they are subject to all basic interactions and they are sensitive to topological effects, as well. Related experiments will be discussed. Recent neutron interferometry experiments based on postselection methods renewed the discussion about quantum nonlocality and the quantum measuring process. It has been shown that interference phenomena can be revived even when the overall interference pattern has lost its contrast. This indicates a persisting coupling in phase space even in cases of spatially separated Schrödinger Cat-like situations. These states are extremely fragile and sensitive against any kind of fluctuations and other decoherence processes. More complete quantum experiments also show that a complete retrieval of quantum states behind an interaction volume becomes impossible in principle.

Physica Scripta•Jan 1, 1998•8 citations

Mysterious Quantum Effects Observed with Neutrons

H. Rauch

Single-particle interference phenomena can be observed with neutrons, and the "entanglement of degrees of freedom", i.e. the contextuality, can be verified and used in further experiments. Entanglement of two photons or atoms is a complementary situation to the double-slit diffraction of a single photon, neutron, or atom. In this respect, neutrons are proper tools for testing quantum mechanics, because they are massive, they couple to electromagnetic fields due to their magnetic moment, and they are subject to all basic interactions, and they are sensitive to topological effects as well. The4π-symmetry of spinor wave functions, the spin-superposition law, and many topological phenomena can be made visible, which shows interesting intrinsic features of quantum physics. Related experiments will be discussed. Deterministic and stochastic partial absorption experiments can be described by Bell-type inequalities. Recent neutron interferometry experiments based on post-selection methods have renewed the discussion about quantum non-locality and the quantum measuring process. It has been shown that interference phenomena can be revived even when the overall interference pattern has lost its contrast. This indicates a persisting coupling in the phase space even in cases of spatially separated Schrödinger cat-like situations. These states are extremely fragile and sensitive against any kind of fluctuations and other de-coherence processes. More complete quantum experiments also show that a complete retrieval of quantum states behind an interaction volume becomes impossible in principle.

Ukrainian Journal of Physics•Apr 30, 2012•0 citations

Observation of quantum interference effects in the frequency domain

X. Y. Zou, Timothy P. Grayson, L. Mandeļ

Interference has been observed in the mixing of signal photons produced by spontaneous down-conversion in two nonlinear crystals, when the optical path difference through the interferometer greatly exceeds the coherence length of the light. The interference shows up as a periodic modulation of the spectrum. We demonstrate that the interference is nonclassical and connected with the entangled state of the signal and idler photons, by transferring the long optical delay from the path of the signal photons to the path of the idler photons. Even though the idlers are not interfering directly, the effect is found to be unchanged, but the interference is lost when the idler photons are blocked. We discuss the extent to which one photon carries the modulated spectrum.

Physical Review Letters•Nov 23, 1992•82 citations
A striking spectral-modulation effect has been observed by means of a proper postselection procedure under conditions where the spatial shift of the wave trains greatly exceeds the coherence length of the neutron beams traversing an interferometer. It is shown that Schr"odinger-cat-like states are created by the superposition of two coherent states generated in the interferometer. These entangled states exhibit, under certain circumstances, characteristic squeezing phenomena, indicating a highly nonclassical behavior. Analogies with optical experiments are discussed.
Decoherence phenomenona in a neutron interferometer are analyzed by simulation of the effects of an environment with magnetic noise fields. Basic calculations and experiments show the validity and limitations of this model system. In particular, loss and recovery of the interference pattern with controllable noise sources in both interferometer arms are discussed in detail. In addition, the decoherence behavior at high interference order, where Schr\"odinger-cat-like states exist in the interferometer, is investigated. While at low interference order a smearing of the interference pattern is observed, at high interference order a smearing of the modulated momentum distribution occurs.
Entanglement of two photons, or atoms is a complementary situation to a double slit situation of a single photon, neutron or atom. With neutrons single particle interference phenomena can be observed and the “entanglement of degrees of freedom”, i.e. contextuality can be verified. In this respect, neutrons are proper tools for testing quantum mechanics because they are massive, they couple to electromagnetic fields due to their magnetic moment and they are subject to all basic interactions, and they are sensitive to topological effects, as well. Related experiments will be discussed. Deterministic and stochastic partial absorption experiments can be described by Bell‐type inequalities. Recent neutron interferometry experiments based on postselection methods renewed the discussion about quantum nonlocality and the quantum measuring process. It has been shown that interference phenomena can be revived even when the overall interference pattern has lost its contrast. This indicates a persisting coupling in phase space even in cases of spatially separated Schrödinger cat‐like situations. These states are extremely fragile and sensitive against any kind of fluctuations and other decoherence processes. More complete quantum experiments also show that a complete retrieval of quantum states behind an interaction volume becomes impossible in principle.
Spectral filtering of the time-separated neutrons passing through an interferometer reconstitutes the interference pattern through the formation of a macroscopic superposition out of the neutron beams and produces squeezed states. In this paper we use matter-waves squeezed states produced in this way to manipulate the rate of expansion of the neutron wave packet. We demonstrate that these quantum states also have nontrivial correlations 〈\ensuremath{\Delta}k\ensuremath{\Delta}x〉. The Heisenberg relation for the spread of the wave packet holds even in this case and the reversal of the wave packet spreading is impossible. However, one can manipulate the rate of the wave packet expansion by changing the phase shift in one of the arms of a neutron interferometer.
Neutrons are proper tools for testing quantum mechanics because they are massive, they couple to electromagnetic fields due to their magnetic moment and they are subject to all basic interactions and they are sensitive to topological effects, as well. Related experiments will be discussed. Recent neutron interferometry experiments based on postselection methods renewed the discussion about quantum nonlocality and the quantum measuring process. It has been shown that interference phenomena can be revived even when the overall interference pattern has lost its contrast. This indicates a persisting coupling in phase space even in cases of spatially separated Schrödinger Cat-like situations. These states are extremely fragile and sensitive against any kind of fluctuations and other decoherence processes. More complete quantum experiments also show that a complete retrieval of quantum states behind an interaction volume becomes impossible in principle.
Single-particle interference phenomena can be observed with neutrons, and the "entanglement of degrees of freedom", i.e. the contextuality, can be verified and used in further experiments. Entanglement of two photons or atoms is a complementary situation to the double-slit diffraction of a single photon, neutron, or atom. In this respect, neutrons are proper tools for testing quantum mechanics, because they are massive, they couple to electromagnetic fields due to their magnetic moment, and they are subject to all basic interactions, and they are sensitive to topological effects as well. The4π-symmetry of spinor wave functions, the spin-superposition law, and many topological phenomena can be made visible, which shows interesting intrinsic features of quantum physics. Related experiments will be discussed. Deterministic and stochastic partial absorption experiments can be described by Bell-type inequalities. Recent neutron interferometry experiments based on post-selection methods have renewed the discussion about quantum non-locality and the quantum measuring process. It has been shown that interference phenomena can be revived even when the overall interference pattern has lost its contrast. This indicates a persisting coupling in the phase space even in cases of spatially separated Schrödinger cat-like situations. These states are extremely fragile and sensitive against any kind of fluctuations and other de-coherence processes. More complete quantum experiments also show that a complete retrieval of quantum states behind an interaction volume becomes impossible in principle.
Interference has been observed in the mixing of signal photons produced by spontaneous down-conversion in two nonlinear crystals, when the optical path difference through the interferometer greatly exceeds the coherence length of the light. The interference shows up as a periodic modulation of the spectrum. We demonstrate that the interference is nonclassical and connected with the entangled state of the signal and idler photons, by transferring the long optical delay from the path of the signal photons to the path of the idler photons. Even though the idlers are not interfering directly, the effect is found to be unchanged, but the interference is lost when the idler photons are blocked. We discuss the extent to which one photon carries the modulated spectrum.