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

arXiv:1701.03074

Evolution of Photon Beams through a Nested Mach-Zehnder Interferometer using Classical States of Light

Anarta Roy, Sibasish Ghosh A

Published Jan 11, 2017• 0 citations
arXivHTMLPDF

Abstract

In this paper, we present a coherent state-vector method which can explain the results of a nested linear Mach-Zehnder Interferometric experiment. Such interferometers are used widely in Quantum Information and Quantum Optics experiments and also in designing quantum circuits. We have specifically considered the case of an experiment by Danan \emph{et al.} (Phys. Rev. Lett. \textbf{111}, 240402 (2013)) where the outcome of the experiment was spooky by our intuitive guesses. However we have been able to show by our method that the results of this experiment is indeed expected within the standard formalism of Quantum Mechanics using any classical state of a single-mode radiation field as the input into the nested interferometric set-up of the aforesaid experiment and thereby looking into the power spectrum of the output beam.

DOI
10.48550/arxiv.1701.03074

Related papers

One-state vector formalism for the evolution of a quantum state through nested Mach-Zehnder interferometers

Karol Bartkiewicz, Antonín Černoch, Dalibor Javůrek +3 more

Linear-optical interferometers play a key role in designing circuits for quantum information processing and quantum communications. Even though nested Mach-Zehnder interferometers appear easy to describe, there are occasions when they provide unintuitive results. This paper explains the results of a highly discussed experiment performed by Danan et al. [Phys. Rev. Lett. 111, 240402 (2013).] using a standard approach. We provide a simple and intuitive one-state vector formalism capable of interpreting their experiment. Additionally, we cross-checked our model with a classical-physics-based approach and found that both models are in complete agreement. We argue that the quantity used in the mentioned experiment is not a suitable which-path witness, producing seemingly contraintuitive results. To circumvent this issue, we establish a more reliable which-path witness and show that it yields well-expected outcomes of the experiment.

arXiv:1410.8454•Physical Review A•Jan 12, 2015•39 citations

Which-way information in a nested Mach-Zehnder interferometer

Václav Potoček, Gergely Ferenczi

Recently, A. Danan et al. [Phys. Rev. Lett. 111, 240402 (2013)] performed a much-discussed experiment in which which-way information was obtained from the light in a nested Mach-Zehnder interferometer by weak measurement. The presented analysis using the two-state vector formalism drew the conclusions that the photons followed disconnected paths. We analyze this experiment using standard quantum optical methods and arrive at analytical expressions that match the experimental results without the need for such disconnected photon paths. We also propose a simple amendment to the experiment capable of displaying new phenomena, highlighting the advantages of our description.

Physical Review A•Aug 17, 2015•41 citations

Interpreting a nested Mach-Zehnder interferometer with classical optics

Pablo L. Saldanha

In an recent work with the title ``Asking Photons Where They Have Been,'' Danan et al. experimentally demonstrate an intriguing behavior of photons in an interferometer [Phys. Rev. Lett. 111, 240402 (2013)]. In their words: ``The photons tell us that they have been in the parts of the interferometer through which they could not pass.'' They interpret the results using the two-state vector formalism of quantum theory and say that, although an explanation of the experimental results in terms of classical electromagnetic waves in the interferometer is possible (and they provide a partial description), it is not so intuitive. Here we present a more detailed classical description of their experimental results, showing that it is actually intuitive. The same description is valid for the quantum wave function of the photons propagating in the interferometer. In particular, we show that it is essential that the wave propagates through all parts of the interferometer to describe the experimental results. We hope that our work helps to give a deeper understanding of these interesting experimental results.

arXiv:1312.7438•Physical Review A•Mar 13, 2014•42 citations

Measuring evolution of a photon in an interferometer with spectrally resolved modes

Marek Bula, Karol Bartkiewicz, Antonín Černoch +4 more

In the year 2013, Danan et al. published a paper [Phys. Rev. Lett. 111, 240402 (2013)] demonstrating a counterintuitive behavior of photons in nested Mach--Zehnder interferometers. The authors then proposed an explanation based on the two-state vector formalism. This experiment and the authors' explanation raised a vivid debate within the scientific community. In this paper, we contribute to the ongoing debate by presenting an alternative experimental implementation of the Danan et al. scheme. We show that no counterintuitive behavior is observed when performing direct spectrally resolved detection.

arXiv:1608.01811•Physical Review A•Nov 9, 2016•9 citations

Comment on “One-state vector formalism for the evolution of a quantum state through nested Mach-Zehnder interferometers”

Lev Vaidman A

Bartkiewicz et al. [Phys. Rev. A 91, 012103 (2015)] provided an alternative analysis of an experiment performed by Danan et al. [Phys. Rev. Lett. 111, 240402 (2013)] which presented surprising evidence regarding the past of photons passing through an interferometer. They argued that the quantity used by Danan et al. is not a suitable which-path witness, and proposed an alternative. The weaknesses of the analysis are discussed, and it is argued that the alternative, analyzed properly, provides no new predictions.

arXiv:1508.07614•Physical Review A•Mar 31, 2016•24 citations

Reply to “Comment on ‘One-state vector formalism for the evolution of a quantum state through nested Mach-Zehnder interferometers’ ”

Karol Bartkiewicz, Antonín Černoch, Dalibor Javůrek +3 more

In our recent paper [Phys. Rev. A 91, 012103 (2015)] we have provided an alternative description of a highly debated experiment by Danan et al. [Phys. Rev. Lett. 111, 240402 (2013)]. The former paper has been recently commented on by Vaidman [Phys. Rev. A 93, 036103 (2016)]. In this Reply we demonstrate that the comments are either invalid or, where valid, do not affect the results of our original paper.

Physical Review A•Mar 31, 2016•7 citations
In this paper, we present a coherent state-vector method which can explain the results of a nested linear Mach-Zehnder Interferometric experiment. Such interferometers are used widely in Quantum Information and Quantum Optics experiments and also in designing quantum circuits. We have specifically considered the case of an experiment by Danan \emph{et al.} (Phys. Rev. Lett. \textbf{111}, 240402 (2013)) where the outcome of the experiment was spooky by our intuitive guesses. However we have been able to show by our method that the results of this experiment is indeed expected within the standard formalism of Quantum Mechanics using any classical state of a single-mode radiation field as the input into the nested interferometric set-up of the aforesaid experiment and thereby looking into the power spectrum of the output beam.
Linear-optical interferometers play a key role in designing circuits for quantum information processing and quantum communications. Even though nested Mach-Zehnder interferometers appear easy to describe, there are occasions when they provide unintuitive results. This paper explains the results of a highly discussed experiment performed by Danan et al. [Phys. Rev. Lett. 111, 240402 (2013).] using a standard approach. We provide a simple and intuitive one-state vector formalism capable of interpreting their experiment. Additionally, we cross-checked our model with a classical-physics-based approach and found that both models are in complete agreement. We argue that the quantity used in the mentioned experiment is not a suitable which-path witness, producing seemingly contraintuitive results. To circumvent this issue, we establish a more reliable which-path witness and show that it yields well-expected outcomes of the experiment.
Recently, A. Danan et al. [Phys. Rev. Lett. 111, 240402 (2013)] performed a much-discussed experiment in which which-way information was obtained from the light in a nested Mach-Zehnder interferometer by weak measurement. The presented analysis using the two-state vector formalism drew the conclusions that the photons followed disconnected paths. We analyze this experiment using standard quantum optical methods and arrive at analytical expressions that match the experimental results without the need for such disconnected photon paths. We also propose a simple amendment to the experiment capable of displaying new phenomena, highlighting the advantages of our description.
In an recent work with the title ``Asking Photons Where They Have Been,'' Danan et al. experimentally demonstrate an intriguing behavior of photons in an interferometer [Phys. Rev. Lett. 111, 240402 (2013)]. In their words: ``The photons tell us that they have been in the parts of the interferometer through which they could not pass.'' They interpret the results using the two-state vector formalism of quantum theory and say that, although an explanation of the experimental results in terms of classical electromagnetic waves in the interferometer is possible (and they provide a partial description), it is not so intuitive. Here we present a more detailed classical description of their experimental results, showing that it is actually intuitive. The same description is valid for the quantum wave function of the photons propagating in the interferometer. In particular, we show that it is essential that the wave propagates through all parts of the interferometer to describe the experimental results. We hope that our work helps to give a deeper understanding of these interesting experimental results.
In the year 2013, Danan et al. published a paper [Phys. Rev. Lett. 111, 240402 (2013)] demonstrating a counterintuitive behavior of photons in nested Mach--Zehnder interferometers. The authors then proposed an explanation based on the two-state vector formalism. This experiment and the authors' explanation raised a vivid debate within the scientific community. In this paper, we contribute to the ongoing debate by presenting an alternative experimental implementation of the Danan et al. scheme. We show that no counterintuitive behavior is observed when performing direct spectrally resolved detection.
Bartkiewicz et al. [Phys. Rev. A 91, 012103 (2015)] provided an alternative analysis of an experiment performed by Danan et al. [Phys. Rev. Lett. 111, 240402 (2013)] which presented surprising evidence regarding the past of photons passing through an interferometer. They argued that the quantity used by Danan et al. is not a suitable which-path witness, and proposed an alternative. The weaknesses of the analysis are discussed, and it is argued that the alternative, analyzed properly, provides no new predictions.