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

Experimental Verification of Wave Packet Collapse Using Fourth-Order Interference

Kazufumi Sakai

Published Sep 1, 2018• 0 citations
OpenAlex

Abstract

The concept of wave packet collapse is the most interesting and difficult to understand assumption of quantum mechanics and it remains an unresolved issue.Therefore, it is necessary to carefully examine its principle and process experimentally.We fabricated a new fourth-order interference apparatus capable of verifying the collapse of a wave packet.Contrary to expectation, a "collapse" was not observed in our experiment.

Related papers

Experimental Approaches to Distinguishing Quantum Collapse from Unitary Evolution: A Weak Measurement Perspective

Peter Renkel

This paper proposes an experiment designed to distinguish between competing interpretations of quantum mechanics: those that involve wave function collapse and those that assume purely unitary evolution. The experiment tests whether an observer can measure a system without collapsing its wave function. To this end, we introduce the concept of an unconscious observer, defined by two criteria: (1) It measures a quantum system and sets the state of another system based on the result. (2) It allows an external experimentalist to infer the measurement outcome by examining the observer's state. The more distinguishable the observer's resulting states, the more it resembles a conventional measurement apparatus. Using weak measurements, the experimentalist probes these states, thereby testing the second criterion. The interference patterns observed in this setup reveal whether collapse has occurred, allowing experimental discrimination between collapse-based and unitary interpretations.

arXiv:2505.19380•May 26, 2025•0 citations

On the possible wave-packet collapse induced by topological disconnectivity and experimental suggestions

Hongwei Xiong

The purpose of this paper is to explore the possibility of a wave-packet collapse induced by topological disconnectivity, based on the discussions of the wave-corpuscle duality. Several experimental suggestions are proposed to test this sort of wave-packet collapse based on quantum interference.

arXiv:0801.1163•Jan 8, 2008•1 citation

N-slit interference and ‘the collapse of the wave function’

Francisco Duarte

It is explained that, in an N-slit experimental configuration the so called ‘collapse of the wave function’ is an unnecessary concept. The explanation begins going back to the original words of Heisenberg on the reduction of the wave packet and continues while considering the measurement process in an N-slit interferometer. In this regard, it is articulated that a clean and direct transition from the superposition probability amplitude to the probability distribution is all that is needed. The discussion includes measurable decoherence in the interferometric domain and the Diósi-Penrose hypothesis.

•Aug 4, 2026•0 citations

Experiment on nonclassical fourth-order interference

Z. Y. Ou, X. Y. Zou, L. J. Wang +1 more

A new fourth-order interference experiment has been carried out and analyzed theoretically in classical and in quantum terms. Two photons produced in the process of parametric down-conversion provide the two inputs to a Mach-Zehnder type of interferometer, while two photodetectors coupled to a coincidence counter measure the output. The coincidence rate, after subtraction of accidentals, exhibits a cosine variation with the optical path difference, in agreement with quantum mechanics, but in disagreement with a classical analysis. By contrast, when two coherent light beams from a He:Ne laser are used as inputs to the interferometer, no fourth-order interference is observed.

Physical Review A•Sep 1, 1990•117 citations

N-slit interference and ‘the collapse of the wave function’

Francisco Duarte

It is explained that, in an N-slit experimental configuration the so called ‘collapse of the wave function’ is an unnecessary concept. The explanation begins going back to the original words of Heisenberg on the reduction of the wave packet and continues while considering the measurement process in an N-slit interferometer. In this regard, it is articulated that a clean and direct transition from the superposition probability amplitude to the probability distribution is all that is needed. The discussion includes measurable decoherence in the interferometric domain and the Diósi-Penrose hypothesis.

•Jul 10, 2026•0 citations

N-slit interference and ‘the collapse of the wave function’

Francisco Duarte

It is explained that, in an N-slit experimental configuration the so called ‘collapse of the wave function’ is an unnecessary concept. The explanation begins going back to the original words of Heisenberg on the reduction of the wave packet and continues while considering the measurement process in an N-slit interferometer. In this regard, it is articulated that a clean and direct transition from the superposition probability amplitude to the probability distribution is all that is needed. The discussion includes measurable decoherence in the interferometric domain and the Diósi-Penrose hypothesis.

•Jul 10, 2026•0 citations
The concept of wave packet collapse is the most interesting and difficult to understand assumption of quantum mechanics and it remains an unresolved issue.Therefore, it is necessary to carefully examine its principle and process experimentally.We fabricated a new fourth-order interference apparatus capable of verifying the collapse of a wave packet.Contrary to expectation, a "collapse" was not observed in our experiment.
This paper proposes an experiment designed to distinguish between competing interpretations of quantum mechanics: those that involve wave function collapse and those that assume purely unitary evolution. The experiment tests whether an observer can measure a system without collapsing its wave function. To this end, we introduce the concept of an unconscious observer, defined by two criteria: (1) It measures a quantum system and sets the state of another system based on the result. (2) It allows an external experimentalist to infer the measurement outcome by examining the observer's state. The more distinguishable the observer's resulting states, the more it resembles a conventional measurement apparatus. Using weak measurements, the experimentalist probes these states, thereby testing the second criterion. The interference patterns observed in this setup reveal whether collapse has occurred, allowing experimental discrimination between collapse-based and unitary interpretations.
It is explained that, in an N-slit experimental configuration the so called ‘collapse of the wave function’ is an unnecessary concept. The explanation begins going back to the original words of Heisenberg on the reduction of the wave packet and continues while considering the measurement process in an N-slit interferometer. In this regard, it is articulated that a clean and direct transition from the superposition probability amplitude to the probability distribution is all that is needed. The discussion includes measurable decoherence in the interferometric domain and the Diósi-Penrose hypothesis.
A new fourth-order interference experiment has been carried out and analyzed theoretically in classical and in quantum terms. Two photons produced in the process of parametric down-conversion provide the two inputs to a Mach-Zehnder type of interferometer, while two photodetectors coupled to a coincidence counter measure the output. The coincidence rate, after subtraction of accidentals, exhibits a cosine variation with the optical path difference, in agreement with quantum mechanics, but in disagreement with a classical analysis. By contrast, when two coherent light beams from a He:Ne laser are used as inputs to the interferometer, no fourth-order interference is observed.
It is explained that, in an N-slit experimental configuration the so called ‘collapse of the wave function’ is an unnecessary concept. The explanation begins going back to the original words of Heisenberg on the reduction of the wave packet and continues while considering the measurement process in an N-slit interferometer. In this regard, it is articulated that a clean and direct transition from the superposition probability amplitude to the probability distribution is all that is needed. The discussion includes measurable decoherence in the interferometric domain and the Diósi-Penrose hypothesis.
It is explained that, in an N-slit experimental configuration the so called ‘collapse of the wave function’ is an unnecessary concept. The explanation begins going back to the original words of Heisenberg on the reduction of the wave packet and continues while considering the measurement process in an N-slit interferometer. In this regard, it is articulated that a clean and direct transition from the superposition probability amplitude to the probability distribution is all that is needed. The discussion includes measurable decoherence in the interferometric domain and the Diósi-Penrose hypothesis.