New state of matter - topological states & topocunductors

It’s all a bit misleading.

Traditional states of matter (gas, solid, liquid, plasma) are defined by the organization and arrangement of the atoms that make up the matter. In other words, by the way the atoms are arranged in space.

But you can have matter that’s in one of those states (say, solid) that also has a “topological” state. Topological states are not determined by the spatial arrangement of the atoms, but are instead determined by the quantum relationship between the particles in the matter.

The topological states is determined by the pattern of the quantum entanglement between the particles. There are multiple possible topological states, all of which require extreme cold - near absolute zero - to be possible.

As for quantum entanglement, that refers to the spooky fact that for certain tiny particles, a property of one particle is tied to a property of another particle. If one particle spins one way, the other has to spin the other. (It gets spookier because you can do experiments that prove that neither particle’s spin is actually determined until you measure it, and once you measure one, the other suddenly has the opposite spin, even thought the two particles are not near each other and cannot have communicated with each other).
 
hmm so rather than the arrangement of atoms in what we traditionally call physical space, it’s about the arrangement of the particle wave’s (that make up the atoms) entanglement with each other?
 
Ender said:
hmm so rather than the arrangement of atoms in what we traditionally call physical space, it’s about the arrangement of the particle wave’s (that make up the atoms) entanglement with each other?
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Essentially, yes.
 
I've never been able to wrap my head around that spooky action at a distance - in fact, every time I get entangled with the idea, my brain collapses...

It would seem to me that we are missing something in that story, like a separate factor, orthogonal to the spin, that is linked to the spin direction and is created/determined at the time of entanglement (freezing), as (unobserved) part of the particle, ensuring that at the time of collapse/measurment, the two particles end up with opposite spin...???
 
Cmaier said:
As for quantum entanglement, that refers to the spooky fact that for certain tiny particles, a property of one particle is tied to a property of another particle. If one particle spins one way, the other has to spin the other. (It gets spookier because you can do experiments that prove that neither particle’s spin is actually determined until you measure it, and once you measure one, the other suddenly has the opposite spin, even thought the two particles are not near each other and cannot have communicated with each other).
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This is just the developers of the simulation who implemented an optimisation they didn't expect to matter for the effects or for us to figure out. "Just render the accurate spin whenever anyone looks at it, until then it doesn't matter". Like LODs
 
cbum said:
I've never been able to wrap my head around that spooky action at a distance - in fact, every time I get entangled with the idea, my brain collapses...

It would seem to me that we are missing something in that story, like a separate factor, orthogonal to the spin, that is linked to the spin direction and is created/determined at the time of entanglement (freezing), as (unobserved) part of the particle, ensuring that at the time of collapse/measurment, the two particles end up with opposite spin...???
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having taken classes in post-graduate-level quantum mechanics, the trick to wrapping your head around it is to just accept it and not try to analogize it to anything you are physically used to. Once I decided that the concept of physical space is just an illusion that quantum particles aren’t subject to, my grades improved. :-) (Same applies to the concept of time, though the experiment where measuring one particle at time X causes the probability wave to collapse for another particle at time X-1 didn’t happen yet by the time I took quantum).
 
Cmaier said:
having taken classes in post-graduate-level quantum mechanics, the trick to wrapping your head around it is to just accept it and not try to analogize it to anything you are physically used to. Once I decided that the concept of physical space is just an illusion that quantum particles aren’t subject to, my grades improved. :-) (Same applies to the concept of time, though the experiment where measuring one particle at time X causes the probability wave to collapse for another particle at time X-1 didn’t happen yet by the time I took quantum).
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For weird abstract thinking like this I strongly recommend listening to/reading some material by Donald Hoffman.

en.wikipedia.org

Donald D. Hoffman - Wikipedia

en.wikipedia.org en.wikipedia.org

Specifiically his "MUI theory".

Not specifically quantum physics related but a mind bending theory on how our senses evolved and how they have absolutely no bearing on physical reality, just what our bodies have determined to be the minimum of useful information to survive. Because things that aren't useful for our brain to perceive and process are just burned energy (and thus, more expense in terms of energy requirements, etc.) for nothing useful. e.g., we can't see in ultraviolet or infrared (like some animals) because for us it is evolutionarily irrelevant to our needs.

With that out of the way, as above - quantum physics is something our brains can't really comprehend (probably because we've never evolved to deal with it), but experimental evidence suggests is legitimate. Just accept the weirdness :D

I'm not a physicist but I suspect the "spooky action at a distance" is essentially because the entangled particles are still "connected" together via a dimension other than time or space(?). i.e., you can move them as far as you like in the 3d space, but without relocating them in some other dimension we can not perceive, they're still "connected".
 
^ … there is a division of thought among physicists, with most accepting ‘this is just how reality is, and the best description we are able to develop’. Others, including the formidable mathematician and cosmologist Roger Penrose, do think there is hidden order. Yet for all his formidable skills and imagination, he hasn’t provided an alternative (to be fair, his tastes lie more in cosmology and pure mathematics).

There have been a number of interesting papers in recent years nibbling away at quantum mechanics and showing - for example - that at least parts of it can be derived from first principles. (I don’t pretend to understand these papers - even though i still read them from time to time! My math/physics BSc dates back to the 1970s!).

I agree…we’re (most of us anyway) simply not built to understand this stuff. It lies too far outside our everyday experience.
 
ArgoDuck said:
There have been a number of interesting papers in recent years nibbling away at quantum mechanics and showing - for example - that at least parts of it can be derived from first principles. (I don’t pretend to understand these papers - even though i still read them from time to time! My math/physics BSc dates back to the 1970s!).
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Yeah, QM is basically this whole mass of stuff we are chipping away at trying to get an insight here or there to help understand it better.

And things like "how does entanglement actually work" gets to pretty foundational concepts of "what is spacetime anyways?" which we really don't know as much about as we thought. As you point out, what we're learning about the universe is way outside our day to day experience, but since our experience includes things such as "space" and "time", it gets rough thinking that those things might even simply be emergent behaviors of some underlying system that we can only probe like one would try to determine how a black box works.

Holographic principle is another one of these things that shows up in the math when looking at the boundaries of entropy (black holes), but we just have no idea wether or not its also applicable to the universe. Maybe, maybe not.

Cmaier said:
But you can have matter that’s in one of those states (say, solid) that also has a “topological” state. Topological states are not determined by the spatial arrangement of the atoms, but are instead determined by the quantum relationship between the particles in the matter.

The topological states is determined by the pattern of the quantum entanglement between the particles. There are multiple possible topological states, all of which require extreme cold - near absolute zero - to be possible.
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I don't think it helps that the Microsoft article in particular is very vague on the topological state they claim to have discovered, just that they are using a topological state for stability of the qubits. Which, apparently superconducting qubits (where superconductivity is a topological state I believe?) are something multiple companies have been working on, so it would help if Microsoft clarified their claims a bit in some way here.
 
One of the key principles to QC is "tunneling". A particle is in a given state, and for it to change state, it has to overcome an energy barrier (energy has to be added to it for its state to change). But, sometimes a particle can change state without the applied energy: it "tunnels" through the energy barrier instead of surmounting it. The states of the qubits may change in distinct ways because some of their particles have tunneled through. The qubit is designed to allow tunneling (which relies largely on the low temperatures) in somewhat predictable ways, which, I think, is where the "topology" part comes in.

Cmaier said:
Once I decided that the concept of physical space is just an illusion that quantum particles aren’t subject to, my grades improved. :-) (Same applies to the concept of time, though the experiment where measuring one particle at time X causes the probability wave to collapse for another particle at time X-1 didn’t happen yet by the time I took quantum).
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Mechanists want to see time in geometric terms, but those are not really applicable. We think of "the present" as a sort of wall between the past and the future, but it is not at all like that. GR and SR tell us that any given location experiences a present that is different from any other location. "Right now" on Mars simply cannot be correlated to right now on Earth. In fact, it has even been possible to measure the GR-effective difference between San Jose and Denver. Your "this very moment" will ultimately not correspond to mine in a meaningful way.

The present moment is not a flat surface, the way it is conveniently depicted in the math, but a blurry diffusion of "about now", which is one reason QM has difficulty with exact measurements (not the only reason).

Add to that the fact that the past is not a physical thing but effectively just information about how we got here. And the one thing we know about information is that it is flexible. The past literally changes as we acquire information pertaining to what happened. It is all Rashomon, all the time. The future is what will probably happened, based on what we thing happened in the past (i.e., "determinism" is nonsense).
 
Yoused said:
One of the key principles to QC is "tunneling". A particle is in a given state, and for it to change state, it has to overcome an energy barrier (energy has to be added to it for its state to change). But, sometimes a particle can change state without the applied energy: it "tunnels" through the energy barrier instead of surmounting it. The states of the qubits may change in distinct ways because some of their particles have tunneled through.
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The way we think about this in quantum mechanics is a little odd. The particle isn’t in a given state. The particle’s state can be described by a probability distribution - in other words, there is a statistical description of where it might be, if it were to be measured. There is a 70% chance it is stuck in a well because of the energy barrier, but a 15% chance it’s over there outside the well on the left, and a 15% chance it’s over there outside the well on the right. We use Schroedinger’s equation to process all those probabilities (you plug in the shape of the well and it spits out probabilities).

Until and unless we measure where it is, there are only probabilities. (Thank’s, Heisenberg!) When we measure the location, the probability function collapses, and then it’s in a particular space (hopefully where we intended it to be). The weird part about QM is that you really have to accept that until it’s measured, it’s both inside and outside the well (and also neither inside nor outside the well). Lots of experiments prove this (double-slit experiments) and it’s completely counter-intuitive.

“Tunneling” is a term used by electrical engineers to describe the fact that even though we erect a barrier to contain the particle, all we have done is affect the probabilities. When we measure the particle’s location it may end up outside the barrier. It didn’t actually tunnel through the barrier - it was never inside the well in the first place.

This is, of course, one of the factors affecting transistor leakage. As the gate gets smaller, you enter the regime where quantum effects apply, and even though we have an electrical potential that should prevent electrons from being on the other side of the gate’s potential barrier, that just means that a given electron is not likely to be there.
 
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Yoused said:
How can you not love Sabine?
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To be honest, I don’t. Don’t get me wrong, I watch her videos and I think she makes good points about certain topics, including the videos you and I both linked to on MS’ topological states, and she explains the science in her videos well. But on other topics … well … consider the below:


She’s all in on the idea that cancel culture and DEI ruined science while ignoring the bullshit inherent in that position - an hypocrisy she often accuses others of. Case in point: An unhealthy fraction of this almost entirely, if not entirely, male author list (Sabine just provided a promotional blurb) have been accused of, or even removed from posts for, sexual misconduct against colleagues and/or bigoted behavior. They then write a book together about how it was cancel culture and not their own fault. Meanwhile as they publish this book, science is actually being dismantled by the anti-DEI/cancel culture warrior ethos they championed and some have the temerity to bemoan it while still claiming it’s the fault of DEI for “going too far”. We've seen what happens when people who agree with them are put in charge and now their whole asses are showing, during a book release no less.

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So while I think she’s a great science communicator, no I can’t say I love her. The irony is she did a video on how she largely agreed with another scientist who said that "scientists should avoid making political statements to avoid undercutting the public's trust their research". And that irony has layers in that not only does she make political statements all the time, including sadly about DEI and cancel culture, but even the very quote, "don't make political statements", is itself a political statement (and if I remember correctly was in context of climate change, so yeah ...). As such, what they really mean is "scientists should avoid making what I consider to be political statements and/or statements I make aren't political and/or it's political statements I consider to be wrongthink that undercut public trust in research" while claiming to value academic freedom, especially from accusations of "wrongthink". As such, this "intellectual dark web" crap is just repackaged Bari Weiss style "freedom of speech warrior" BS for scientists.
 
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