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:2605.22218

Three sins against physics by an exaggerated quantum information perspective

Valerio Scarani

quant-phSubmitted May 21, 2026• Announced May 22, 2026• 0 citations
arXivHTMLPDF

Abstract

I point out three ways in which the perspective of quantum information may lead to distorted claims about physics: forgetting that light does not need to be quantised to show coherence; ignoring the generators of unitary evolutions; and approaching the discovery of nature as a fight against an adversary.

Related papers

Quantum Information is physical too

Terry Rudolph

We discuss the physical nature of quantum information, in particular focussing on tasks that are achievable by some physical realizations of qubits but not by others.

arXiv:quant-ph/9904037•Apr 8, 1999•1 citation

QUANTUM ARCHITECTONICS: THE PASSIVE PATH TO SCALE

Rowan Brad Quni-Gudzinas

The current approach to building quantum computers relies on a strategy of brute force intervention. Engineers attempt to force fragile quantum states to survive by constantly correcting their errors with external machinery. This method treats the quantum bit, or qubit, as an inherently unstable object that must be propped up. It assumes that if we simply build faster control loops, we can outrun the natural decay of the system. However, this perspective ignores the fundamental cost of fighting nature. Every time we correct an error, we are fighting against the natural tendency of the universe to increase disorder. This fight requires energy, and that energy must go somewhere. The reliance on active error correction creates a vicious cycle of energy consumption. As we add more qubits to the system, the number of errors increases. To fix these errors, we need more control hardware and more processing power. This additional hardware generates heat, which disturbs the sensitive quantum states even more. The more we try to fix the system, the more we disturb it. It is like trying to calm a pool of water by slapping the waves flat. The very act of intervention creates new ripples that require further correction. This scaling problem is not just a matter of engineering difficulty; it is a matter of physics. There is a limit to how fast and how efficiently we can extract entropy, or disorder, from a system. Current architectures are approaching this limit rapidly. We are building systems that require massive cooling infrastructure just to keep the control electronics from melting the qubits. This is not a sustainable path to a useful computer. We need a fundamentally different approach. The brute force method also introduces a complexity bottleneck. The software required to track and correct errors in real-time is becoming impossibly complex. We are trying to simulate a perfect machine using imperfect parts, and the overhead is crushing. The ratio of physical qubits needed to build one logical qubit is skyrocketing. We are spending all our resources on error correction, leaving little for actual computation. This is the definition of a diminishing return. We must recognize that the “active” paradigm is a trap. It lures us in with the promise of total control, but it hides the thermodynamic bill. That bill is coming due, and it is higher than we can pay. We cannot simply scale our way out of this problem with more power. We need to stop fighting the environment and start designing systems that are naturally stable. We need to move from active correction to passive protection.

•Feb 7, 2026•0 citations

The Message of the Quantum?

Martin Däumer

We criticize speculations to the effect that quantum mechanics is fundamentally about information. We do this by pointing out how unfounded such speculations in fact are. Our analysis focuses on the dubious claims of this kind recently made by Anton Zeilinger.

arXiv:quant-ph/0604173•AIP conference proceedings•Jan 1, 2006•13 citations

Perspectives Without Physical Grounds: A Critique of Embodiment and Local Unitarity in Relational Quantum Mechanics

Ahmed Albezawi

Di Biagio and Rovelli’s recent reformulation of Relational Quantum Mechanics (RQM) introduces relative facts grounded in commutative subalgebras and relative Shannoninformation, claiming to provide a physically embodied, naturalistic, and locally coherent account of quantum phenomena. We identify a structural inconsistency in this programme by analysing a scenario in which observer A remains entirely unperturbed while a remote observer B measures a complementary observable of a shared entangled system S. We prove rigorously that (i) A’s local reduced density matrix is invariant under this remote action, (ii) the relative information I(Z|A) nonetheless drops from maximal to minimal, and (iii) no local unitary acting on H(A) can generate this change, since local unitaries preserve mutual information. These three results jointly entail that the evolution of A’s perspective is not generated by any local physical process, directly contradicting the paper’s explicit commitment to physical embodiment and local autonomy of perspectives. We argue this is not a technical defect but a foundational tension: RQM cannot simultaneously maintain that perspectives are locally embodied in physical correlations, that they evolve unitarily when no interaction occurs, and that remote complementary measurements alter local relative facts. Without additional structure specifying the dynamics ofperspectives under non-local entanglement changes, RQM’s naturalistic programmeis internally inconsistent at this level. We further argue that no-signaling doesnot rescue the ontological claim, and compare the problem’s severity to analogous nonlocality in other interpretations.

•May 11, 2026•0 citations

Quantum mechanics as quantum information, mostly

Christopher A. Fuchs

In this paper, I try to cause some good-natured trouble. The issue is, when will we ever stop burdening the taxpayer with conferences devoted to the quantum foundations? The suspicion is expressed that no end will be in sight until a means is found to reduce quantum theory to two or three statements of crisp physical (rather than abstract, axiomatic) significance. In this regard, no tool appears better calibrated for a direct assault than quantum information theory. Far from a strained application of the latest fad to a time-honoured problem, this method holds promise precisely because a large part—but not all—of the structure of quantum theory has always concerned information. It is just that the physics community needs reminding.

Journal of Modern Optics•Jan 1, 2003•139 citations

Perspectives Without Physical Grounds: A Critique of Embodiment and Local Unitarity in Relational Quantum Mechanics

Ahmed Albezawi

Di Biagio and Rovelli’s recent reformulation of Relational Quantum Mechanics (RQM) introduces relative facts grounded in commutative subalgebras and relative Shannon information, claiming to provide a physically embodied, naturalistic, and locally coherent account of quantum phenomena. We identify a structural inconsistency in this programme by analysing a scenario in which observer A remains entirely unperturbed while a remote observer B measures a complementary observable of ashared entangled system S. We prove rigorously that (i) A’s local reduced density matrix is invariant under this remote action, (ii) the relative information I(Z|A) nonetheless drops from maximal to minimal, and (iii) no local unitary acting on H(A) can generate this change, since local unitaries preserve mutual information. Thesethree results jointly entail that the evolution of A’s perspective is not generated byany local physical process, directly contradicting the paper’s explicit commitment to physical embodiment and local autonomy of perspectives. We argue this is not atechnical defect but a foundational tension: RQM cannot simultaneously maintainthat perspectives are locally embodied in physical correlations, that they evolve unitarily when no interaction occurs, and that remote complementary measurementsalter local relative facts. Without additional structure specifying the dynamics of perspectives under non-local entanglement changes, RQM’s naturalistic programmeis internally inconsistent at this level. We further argue that no-signaling doesnot rescue the ontological claim, and compare the problem’s severity to analogousnonlocality in other interpretations.

•May 11, 2026•0 citations
The current approach to building quantum computers relies on a strategy of brute force intervention. Engineers attempt to force fragile quantum states to survive by constantly correcting their errors with external machinery. This method treats the quantum bit, or qubit, as an inherently unstable object that must be propped up. It assumes that if we simply build faster control loops, we can outrun the natural decay of the system. However, this perspective ignores the fundamental cost of fighting nature. Every time we correct an error, we are fighting against the natural tendency of the universe to increase disorder. This fight requires energy, and that energy must go somewhere. The reliance on active error correction creates a vicious cycle of energy consumption. As we add more qubits to the system, the number of errors increases. To fix these errors, we need more control hardware and more processing power. This additional hardware generates heat, which disturbs the sensitive quantum states even more. The more we try to fix the system, the more we disturb it. It is like trying to calm a pool of water by slapping the waves flat. The very act of intervention creates new ripples that require further correction. This scaling problem is not just a matter of engineering difficulty; it is a matter of physics. There is a limit to how fast and how efficiently we can extract entropy, or disorder, from a system. Current architectures are approaching this limit rapidly. We are building systems that require massive cooling infrastructure just to keep the control electronics from melting the qubits. This is not a sustainable path to a useful computer. We need a fundamentally different approach. The brute force method also introduces a complexity bottleneck. The software required to track and correct errors in real-time is becoming impossibly complex. We are trying to simulate a perfect machine using imperfect parts, and the overhead is crushing. The ratio of physical qubits needed to build one logical qubit is skyrocketing. We are spending all our resources on error correction, leaving little for actual computation. This is the definition of a diminishing return. We must recognize that the “active” paradigm is a trap. It lures us in with the promise of total control, but it hides the thermodynamic bill. That bill is coming due, and it is higher than we can pay. We cannot simply scale our way out of this problem with more power. We need to stop fighting the environment and start designing systems that are naturally stable. We need to move from active correction to passive protection.
Di Biagio and Rovelli’s recent reformulation of Relational Quantum Mechanics (RQM) introduces relative facts grounded in commutative subalgebras and relative Shannoninformation, claiming to provide a physically embodied, naturalistic, and locally coherent account of quantum phenomena. We identify a structural inconsistency in this programme by analysing a scenario in which observer A remains entirely unperturbed while a remote observer B measures a complementary observable of a shared entangled system S. We prove rigorously that (i) A’s local reduced density matrix is invariant under this remote action, (ii) the relative information I(Z|A) nonetheless drops from maximal to minimal, and (iii) no local unitary acting on H(A) can generate this change, since local unitaries preserve mutual information. These three results jointly entail that the evolution of A’s perspective is not generated by any local physical process, directly contradicting the paper’s explicit commitment to physical embodiment and local autonomy of perspectives. We argue this is not a technical defect but a foundational tension: RQM cannot simultaneously maintain that perspectives are locally embodied in physical correlations, that they evolve unitarily when no interaction occurs, and that remote complementary measurements alter local relative facts. Without additional structure specifying the dynamics ofperspectives under non-local entanglement changes, RQM’s naturalistic programmeis internally inconsistent at this level. We further argue that no-signaling doesnot rescue the ontological claim, and compare the problem’s severity to analogous nonlocality in other interpretations.
In this paper, I try to cause some good-natured trouble. The issue is, when will we ever stop burdening the taxpayer with conferences devoted to the quantum foundations? The suspicion is expressed that no end will be in sight until a means is found to reduce quantum theory to two or three statements of crisp physical (rather than abstract, axiomatic) significance. In this regard, no tool appears better calibrated for a direct assault than quantum information theory. Far from a strained application of the latest fad to a time-honoured problem, this method holds promise precisely because a large part—but not all—of the structure of quantum theory has always concerned information. It is just that the physics community needs reminding.
Di Biagio and Rovelli’s recent reformulation of Relational Quantum Mechanics (RQM) introduces relative facts grounded in commutative subalgebras and relative Shannon information, claiming to provide a physically embodied, naturalistic, and locally coherent account of quantum phenomena. We identify a structural inconsistency in this programme by analysing a scenario in which observer A remains entirely unperturbed while a remote observer B measures a complementary observable of ashared entangled system S. We prove rigorously that (i) A’s local reduced density matrix is invariant under this remote action, (ii) the relative information I(Z|A) nonetheless drops from maximal to minimal, and (iii) no local unitary acting on H(A) can generate this change, since local unitaries preserve mutual information. Thesethree results jointly entail that the evolution of A’s perspective is not generated byany local physical process, directly contradicting the paper’s explicit commitment to physical embodiment and local autonomy of perspectives. We argue this is not atechnical defect but a foundational tension: RQM cannot simultaneously maintainthat perspectives are locally embodied in physical correlations, that they evolve unitarily when no interaction occurs, and that remote complementary measurementsalter local relative facts. Without additional structure specifying the dynamics of perspectives under non-local entanglement changes, RQM’s naturalistic programmeis internally inconsistent at this level. We further argue that no-signaling doesnot rescue the ontological claim, and compare the problem’s severity to analogousnonlocality in other interpretations.