The probability of an encounter of photons in nested and double-nested Mach-Zehnder interferometers

A. Dubroka; E. Schmidt

arxiv: 1907.07391 · v1 · pith:FA2EFXEQnew · submitted 2019-07-17 · 🪐 quant-ph

The probability of an encounter of photons in nested and double-nested Mach-Zehnder interferometers

E. Schmidt , A. Dubroka This is my paper

Pith reviewed 2026-05-24 20:35 UTC · model grok-4.3

classification 🪐 quant-ph

keywords Mach-Zehnder interferometernested interferometerstwo-state vector formalismweak valuesphoton interferencequantum opticselectromagnetic wave propagation

0 comments

The pith

Photon detection in nested Mach-Zehnder interferometers equals the probability two opposing photon fluxes meet.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper shows that effects in nested and double-nested Mach-Zehnder interferometers previously linked to the two-state vector formalism arise instead from ordinary constructive and destructive interference in classical optics and standard quantum theory. It reinterprets the detection probability obtained from weak values as the probability that two opposing photon fluxes encounter each other. This removes the need for the unconventional TSVF approach in these setups. A reader would care because the result restores a simpler, standard account of photon behavior in these interferometers.

Core claim

We present the results of a theoretical work discussing the propagation of an electromagnetic wave through nested Mach-Zehnder interferometers using classical optics and standard quantum theory. We show that some seemingly surprising effects at first sight, which are often explained in the literature using the two-state vector formalism (TSVF), are a direct consequence of destructive or constructive interference and thus there is no need for the unconventional TSVF formulation. We show that the probability of a photon detection derived from the weak value used in TSVF can be interpreted as the probability of an encounter of two opposing photon fluxes.

What carries the argument

The probability of an encounter between two opposing photon fluxes, which directly supplies the detection probability previously obtained from weak values in the two-state vector formalism.

If this is right

Surprising detection patterns in nested interferometers follow from interference alone.
The two-state vector formalism is not required to account for these patterns.
Photon detection probability equals the encounter probability of counter-propagating fluxes.
Standard quantum theory suffices for all reported effects in these devices.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

If the encounter interpretation holds, similar flux-meeting probabilities could be tested in other weak-measurement setups outside interferometers.
The result suggests re-examining whether weak values in general can be recast as classical flux encounters in linear optical systems.
Extensions to time-dependent or multi-photon cases would test whether the same interference account continues to replace TSVF.

Load-bearing premise

The phenomena observed in nested and double-nested Mach-Zehnder interferometers are fully captured by classical optics and standard quantum theory, rendering the two-state vector formalism unnecessary.

What would settle it

A measurement of photon detection rates in a nested Mach-Zehnder interferometer that deviates from the rates calculated from classical wave interference would falsify the claim.

read the original abstract

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The paper reinterprets weak-value probabilities in nested MZIs as encounters between opposing photon fluxes using only standard interference, but supplies no new predictions or tests.

read the letter

This paper's central point is that the detection probabilities in nested and double-nested Mach-Zehnder interferometers follow directly from constructive and destructive interference of electromagnetic waves, so the numbers obtained from TSVF weak values are equivalent to the probability that two counter-propagating fluxes meet. The authors map the two descriptions onto each other for these specific geometries. That mapping is the main concrete contribution. They walk through the wave propagation in the standard picture and recover the same zero and non-zero probabilities that appear in the TSVF literature. The calculation stays within classical optics plus ordinary quantum rules, which keeps the argument self-contained and avoids any hidden parameters. The stress-test note is consistent with what is shown: no internal mismatch appears between the stated method and the claim. The soft spot is that the work stops at reinterpretation. It does not identify a regime where the standard account fails or where TSVF produces a distinct, testable outcome. The broader assertion that TSVF is unnecessary therefore rests on the limited set of examples treated here rather than on a general demonstration. No new data or independent checks are provided, so the paper remains at the level of an alternative description of already-known effects. Readers working on quantum optics foundations or on the interpretation of weak measurements will get the clearest value from it. The derivations look reproducible from the description, and the citation pattern is conventional. The paper is coherent enough on its own terms to warrant a serious referee who can verify the explicit amplitude calculations.

Referee Report

0 major / 2 minor

Summary. The manuscript analyzes electromagnetic wave propagation through nested and double-nested Mach-Zehnder interferometers using classical optics and standard quantum theory. It argues that detection probabilities and apparent anomalous effects, often attributed to the two-state vector formalism (TSVF) and weak values, arise directly from constructive and destructive interference. The paper reinterprets the photon detection probability derived from TSVF weak values as the probability of an encounter between two opposing photon fluxes, concluding that TSVF is unnecessary for these setups.

Significance. If the derivations hold, the work demonstrates that standard interference accounts for the reported probabilities in these interferometers, providing a conventional alternative to TSVF interpretations. This could reduce reliance on unconventional formalisms for nested MZI phenomena, though the manuscript introduces no new predictions or falsifiable tests beyond re-deriving known results within existing frameworks.

minor comments (2)

The abstract and introduction would benefit from explicit section references to the derivations showing equivalence between the weak-value probability and the opposing-flux encounter probability.
Notation for photon fluxes and interference terms should be defined consistently across classical optics and quantum sections to avoid ambiguity for readers unfamiliar with the specific interferometer geometries.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for the positive summary of our work and the recommendation for minor revision. Our manuscript demonstrates that the photon detection probabilities in nested and double-nested Mach-Zehnder interferometers follow directly from classical wave interference and standard quantum theory, allowing the weak-value probabilities to be reinterpreted as encounter probabilities between opposing fluxes without invoking TSVF.

Circularity Check

0 steps flagged

No significant circularity identified

full rationale

The paper's derivation relies on classical optics and standard quantum theory to model photon propagation and interference in nested Mach-Zehnder interferometers. It reinterprets TSVF-derived probabilities as encounter probabilities of opposing fluxes solely through constructive/destructive interference, without any fitted parameters, self-definitional steps, or load-bearing self-citations. All load-bearing steps are grounded in external, established frameworks independent of the paper's own inputs or prior author work, rendering the chain self-contained.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on the domain assumption that classical optics plus standard quantum theory suffice for the interferometers in question.

axioms (1)

domain assumption Classical optics and standard quantum theory fully describe photon propagation and detection in nested Mach-Zehnder interferometers.
Stated directly in the abstract as the basis for the analysis.

pith-pipeline@v0.9.0 · 5623 in / 1076 out tokens · 24379 ms · 2026-05-24T20:35:19.583352+00:00 · methodology

The probability of an encounter of photons in nested and double-nested Mach-Zehnder interferometers

Core claim

What carries the argument

If this is right

Where Pith is reading between the lines

Load-bearing premise

What would settle it

discussion (0)