A new study published in Nature Physics introduces a theory of electron-phonon coupling that is affected by the quantum geometry of the electronic wavefunctions
In quantum field theory (standard model of particle physics), photons are the quanta of a field (naturally identified with the quantized electromagnetic field, or U(1) gauge field), which evolves in a nonlinear way that is coupled not only to itself, but also the electron field (as photons are the carrier of the electromagnetic interaction). It seems to me that the concept of “photon” (the particle) is one that is useful in some contexts (like modeling the possible interactions between two electrons in a Feynman diagram), but that the concept of photon is not a fundamental constituent of reality. Certainly, wave packets of the field can interact by way of superposition and thereby altering the space-time evolution of the field through its coupling constant.
Superposition is valid in vacuum, well, actually, until the photons have enough energy to colide and form an electron-positron pair.
It's also valid in most transparent material, again, assuming
1) each photon has no enough energy for example to extract an electron form the material like in the photoelectric effect, or creating an electron and a hole in a semiconductor, or ...
2) there are not enough photons, so you can model the effect using linear equations
And there are weird materials where the non linear effects are easy to trigger.
The conclusion is that superposition is only a nice approximation in the easy case.
To remedy this problem, Chen and his colleagues investigated if there could be entangled photons within this axon-myelin system that could, though the magic of quantum entanglement, communicate instantly across the involved distances.
yawn Another day, another garbage pop sci article perpetuating falsehoods about quantum entanglement.
I think the pop-sci writer simply didn’t choose a good wording - the original paper is simply about how the (consciousness-orchestrated?) synchronized activities of millions of neurons may be linked to “cylindrical cavity formed by a myelin sheath can facilitate spontaneous photon emission from the vibrational modes and generate a significant number of entangled photon pairs”.
When we don’t have a way to define consciousness and its (let’s called it) orchestration, the notion of “communication” is none-sensible. It’s like if we look at Shor’s algorithm, its BQP efficiency isn’t really due to any “communication” among the q-bits - but more as a kind of “probabilities collapsing” as they go through these quantum gates.
Td;dr I think the phys.org writer is just trying to make it sound more exciting by unfortunately using a miss-leading word
I think are overstating the strength of the No Communication Theorem. It does not state that communication via quantum entanglement is impossible in all cases; the theorem is weaker. From the article you linked:
“Being only a sufficient condition there can be extra cases where communication is not allowed and there can be also cases where is still possible to communicate through the quantum channel encoding more than the classical information.”
Consider the quoted assumption (again from the article you shared)
“An important assumption going into the theorem is that neither Alice nor Bob is allowed, in any way, to affect the preparation of the initial state. If Alice were allowed to take part in the preparation of the initial state, it would be trivially easy for her to encode a message into it; thus neither Alice nor Bob participates in the preparation of the initial state.”
Now it’s not clear to me how to correctly map this assumption onto the papers context. Who are the observers? Are they a pair of neurons on the ends of the axon? Are they neighboring myelin sheaths? Is it fair to assert that these observers have no role in preparation of the initial quantum state? Seeing as the entangled photons in the paper are produced as the result of chemical reactions occurring within the confines of the myelin sheaths causing excitation of carbon atoms and subsequent radiation of infrared photons, do the particular assumptions of the No Communication Theorem (a thought experiment that translates those assumptions into definite mathematical propositions) make sense?
Where are we drawing the boundary between these classical observers and the quantum system? Are there even any classical observers at all?
Your yawning dismissal strikes me as an overconfident conclusion.
I had always assumed that activity in the brain was unsynchronized and that it is that which produces the necessary randomness through race conditions. I am considering the need to find synchronization as making some sort of computer analogy which doesn't exist.
Brain activity is highly synchronized, at least according to the definition used by neuroscientists. Brain waves operate at certain hertz based on your level of arousal. https://en.wikipedia.org/wiki/Neural_oscillation
The brain waves drive the synchronization process by triggering inhibition in neurons not in the targeted subgroup.
There are different frequency waves that operate over different timescales and distances and are typically involved in different types of functional activity.
Comments
Traditional belief: photons do not interact with photons, photons are massless according to the mass energy relation.
New findings: Photons interact as phonons in matter.
"Quantum entangled photons react to Earth's spin" (2024) https://news.ycombinator.com/item?id=40720147 :
"New theory links quantum geometry to electron-phonon coupling" (2024) https://news.ycombinator.com/item?id=40663966 https://phys.org/news/2024-06-theory-links-quantum-geometry-... :
In quantum field theory (standard model of particle physics), photons are the quanta of a field (naturally identified with the quantized electromagnetic field, or U(1) gauge field), which evolves in a nonlinear way that is coupled not only to itself, but also the electron field (as photons are the carrier of the electromagnetic interaction). It seems to me that the concept of “photon” (the particle) is one that is useful in some contexts (like modeling the possible interactions between two electrons in a Feynman diagram), but that the concept of photon is not a fundamental constituent of reality. Certainly, wave packets of the field can interact by way of superposition and thereby altering the space-time evolution of the field through its coupling constant.
The field of nonlinear optics deals with photon-photon interactions in matter, and has been around for almost a century.
https://en.wikipedia.org/wiki/Nonlinear_optics
Do they model photons as rays, vectors, particles, waves, or fluids?
https://en.wikipedia.org/wiki/Nonlinear_optics :
But phonons are quantum waves in or through matter and the superposition principle holds with phonons AFAIU
Superposition is valid in vacuum, well, actually, until the photons have enough energy to colide and form an electron-positron pair.
It's also valid in most transparent material, again, assuming
1) each photon has no enough energy for example to extract an electron form the material like in the photoelectric effect, or creating an electron and a hole in a semiconductor, or ...
2) there are not enough photons, so you can model the effect using linear equations
And there are weird materials where the non linear effects are easy to trigger.
The conclusion is that superposition is only a nice approximation in the easy case.
yawn Another day, another garbage pop sci article perpetuating falsehoods about quantum entanglement.
https://en.m.wikipedia.org/wiki/No-communication_theorem
To be fair that is not the wordings in the original paper. https://arxiv.org/abs/2401.11682
I think the pop-sci writer simply didn’t choose a good wording - the original paper is simply about how the (consciousness-orchestrated?) synchronized activities of millions of neurons may be linked to “cylindrical cavity formed by a myelin sheath can facilitate spontaneous photon emission from the vibrational modes and generate a significant number of entangled photon pairs”.
When we don’t have a way to define consciousness and its (let’s called it) orchestration, the notion of “communication” is none-sensible. It’s like if we look at Shor’s algorithm, its BQP efficiency isn’t really due to any “communication” among the q-bits - but more as a kind of “probabilities collapsing” as they go through these quantum gates.
Td;dr I think the phys.org writer is just trying to make it sound more exciting by unfortunately using a miss-leading word
I think are overstating the strength of the No Communication Theorem. It does not state that communication via quantum entanglement is impossible in all cases; the theorem is weaker. From the article you linked:
“Being only a sufficient condition there can be extra cases where communication is not allowed and there can be also cases where is still possible to communicate through the quantum channel encoding more than the classical information.”
Consider the quoted assumption (again from the article you shared)
“An important assumption going into the theorem is that neither Alice nor Bob is allowed, in any way, to affect the preparation of the initial state. If Alice were allowed to take part in the preparation of the initial state, it would be trivially easy for her to encode a message into it; thus neither Alice nor Bob participates in the preparation of the initial state.”
Now it’s not clear to me how to correctly map this assumption onto the papers context. Who are the observers? Are they a pair of neurons on the ends of the axon? Are they neighboring myelin sheaths? Is it fair to assert that these observers have no role in preparation of the initial quantum state? Seeing as the entangled photons in the paper are produced as the result of chemical reactions occurring within the confines of the myelin sheaths causing excitation of carbon atoms and subsequent radiation of infrared photons, do the particular assumptions of the No Communication Theorem (a thought experiment that translates those assumptions into definite mathematical propositions) make sense?
Where are we drawing the boundary between these classical observers and the quantum system? Are there even any classical observers at all?
Your yawning dismissal strikes me as an overconfident conclusion.
I had always assumed that activity in the brain was unsynchronized and that it is that which produces the necessary randomness through race conditions. I am considering the need to find synchronization as making some sort of computer analogy which doesn't exist.
Brain activity is highly synchronized, at least according to the definition used by neuroscientists. Brain waves operate at certain hertz based on your level of arousal. https://en.wikipedia.org/wiki/Neural_oscillation
Brain waves also synchronize to other brain waves; "interbrain synchrony"
- "The Social Benefits of Getting Our Brains in Sync" (2024) https://www.quantamagazine.org/the-social-benefits-of-gettin...
But that might be just like the sea has waves?
The brain waves drive the synchronization process by triggering inhibition in neurons not in the targeted subgroup.
There are different frequency waves that operate over different timescales and distances and are typically involved in different types of functional activity.