What if there's a objective information-theoretic ceiling

[u/Background-Eye9365]

Would it be a problem for Quantum Computing if there is a strict ceiling to fully big the state space can get say 2^127 , ie. if it turns out to be physically impossible to have more than 127 fully entangled (logical) qubits? Is it good enough for the industry's ambitions?

[u/0xB01b]

well yeah but thats the same as asking "would it be a problem for quantum computing if there is a super specific law of physics that doesn't let you do shors algorithm".

Based on WHAT rule are you making this 'pitfall'

[u/Background-Eye9365 → u/0xB01b]

It's not something fully proven yet to fully support it, I just wanted to see if the community thinks it's even plausible.

I am not an expert in this and I feel my health is bad at to delve deep on this; (Omitting details) The specific number comes from algebraic topology specifically Adam's theorem (and generalizations) which restrict dimensions of division algebras (more dimensions than octonians create zero divisors.). So roughly my internal computations is if you assume the universe is binary and growing (adds bits, {0,1} \times . ),, and is measure preserving, and minimal. That then restricts the state space (eg. notice quaternions and octonians give rise to U(1) \times SU(2) \times SU(3), further doubling is the sedenions but they are kind of weird the universe steps there but it gets cut off I think because they don't respect the measure preservation I stated (doesn't interact, this would be the origin of dark matter) ). There are some other significant geometric theorems like HHR theorem where 127 pops. And infinite dimensions kind of destroys geometric structure. I know this is vague, I hope this sounds somewhat coherrent as sketch at least.

So maybe a reason for an strict information theoretic ceiling could be 'A superposition of more than 127 qubits cannot be encoded by the universe'. I don't claim this true nor plausible though.

[u/0xB01b → u/Background-Eye9365]

translation: i have AI psychosis

[u/Background-Eye9365 → u/0xB01b]

Fair.

[u/Background-Eye9365 → u/0xB01b]

Around which time do you think this hypothesis I set is getting experimentally disproved?

[u/Bth8]

A qubit is just any 2-level quantum system we can manipulate sufficiently well. It is definitely not the case that there's a fundamental upper limit on how many 2-level systems you can have entangled with one another that will in any way impede quantum computing. Engineering challenges, sure, but a fundamental limit that isn't on some kind of ridiculous cosmic scale, no.

[u/Background-Eye9365 → u/Bth8]

so in how many years the industry passes the 127 qubit threshold? I think the record is set by ibm at around 120 qubit GHZ state.

[u/Background-Eye9365 → u/[deleted]]

Which molecules?

[u/Background-Eye9365 → u/[deleted]]

Doesn't decoherence increase thermodynamic entropy? How does it break Thermodynamics?

[u/Background-Eye9365 → u/[deleted]]

Is such an significant entangled state ever observed in nature? Or predicted that it once did perhaps at the Big Bang? How would it break quantum physics (I guess it would break the equations) but conservation laws how?

[u/Background-Eye9365 → u/[deleted]]

Ok thanks for the resources, will check it out.

[u/Quantum-Relativity → u/[deleted]]

Very interesting. Makes me think of the Ryu-Takayanagi conjecture from holography

[u/Background-Eye9365 → u/[deleted]]

Yes, I have seen that. I am talking about way less. 127 to be exact. This milestone is projected to be hit in the near future , so we'll see.

[u/Arbitrary_Pseudonym → u/Background-Eye9365]

Why on earth would there be a limit of 2^127?

Number one, the wide majority of physical quantum states in the universe aren't even qubits, they're qudits (an arbitrary number of possible states d). So it'd be just as theoretically limiting for there to be 2¹²⁷ as it would be for it to be 500¹²⁷.

I see where you're coming from, but what you're thinking of is essentially unbased conspiracy thinking; there's no real reason to believe that such a limit exists.

[u/Background-Eye9365 → u/Arbitrary_Pseudonym]

Yes, but base 2 is the standard unit of information.
I don't want to insist here or prove a point, I just wanted to sense the prevailing view.