The 500 phases of matter: Entering a new phase

Dec 21, 2012
Xiao-Gang Wen and the 500 phases of matter
Artist's impression of a string-net of light and electrons. String-nets are a theoretical kind of topologically ordered matter.

(Phys.org)—Forget solid, liquid, and gas: there are in fact more than 500 phases of matter. In a major paper in today's issue of Science, Perimeter Faculty member Xiao-Gang Wen reveals a modern reclassification of all of them. Using modern mathematics, Wen and collaborators reveal a new system which can, at last, successfully classify symmetry-protected phases of matter. Their new classification system will provide insight about these quantum phases of matter, which may in turn increase our ability to design states of matter for use in superconductors or quantum computers. This paper, titled, "Symmetry-Protected Topological Orders in Interacting Bosonic Systems," is a revealing look at the intricate and fascinating world of quantum entanglement, and an important step toward a modern reclassification of all phases of matter.

– the branch of physics responsible for discovering and describing most of these phases – has traditionally classified phases by the way their fundamental building blocks – usually atoms – are arranged. The key is something called symmetry.

To understand symmetry, imagine flying through in an impossibly tiny ship: the atoms would swirl randomly around you and every direction – whether up, down, or sideways – would be the same. The technical term for this is "symmetry" – and liquids are highly symmetric. Crystal ice, another phase of water, is less symmetric. If you flew through ice in the same way, you would see the straight rows of passing as regularly as the girders of an unfinished skyscraper. Certain angles would give you different views. Certain paths would be blocked, others wide open. Ice has many symmetries – every "floor" and every "room" would look the same, for instance – but physicists would say that the high symmetry of liquid water is broken.

Classifying the phases of matter by describing their symmetries and where and how those symmetries break is known as the Landau paradigm. More than simply a way of arranging the phases of matter into a chart, Landau's theory is a powerful tool which both guides scientists in discovering new phases of matter and helps them grapple with the behaviours of the known phases. Physicists were so pleased with Landau's theory that for a long time they believed that all phases of matter could be described by symmetries. That's why it was such an eye-opening experience when they discovered a handful of phases that Landau couldn't describe.

Beginning in the 1980s, condensed matter researchers, including Xiao-Gang Wen – now a faculty member at Perimeter Institute – investigated new quantum systems where numerous ground states existed with the same symmetry. Wen pointed out that those new states contain a new kind of order: topological order. Topological order is a quantum mechanical phenomenon: it is not related to the symmetry of the ground state, but instead to the global properties of the ground state's wave function. Therefore, it transcends the Landau paradigm, which is based on classical physics concepts.

Topological order is a more general understanding of quantum phases and the transitions between them. In the new framework, the phases of matter were described not by the patterns of symmetry in the ground state, but by the patterns of a decidedly quantum property – entanglement. When two particles are entangled, certain measurements performed on one of them immediately affect the other, no matter how far apart the particles are. The patterns of such quantum effects, unlike the patterns of the atomic positions, could not be described by their symmetries. If you were to describe a city as a topologically ordered state from the cockpit of your impossibly tiny ship, you'd no longer be describing the girders and buildings of the crystals you passed, but rather invisible connections between them – rather like describing a city based on the information flow in its telephone system.

This more general description of matter developed by Wen and collaborators was powerful – but there were still a few phases that didn't fit. Specifically, there were a set of short-range entangled phases that did not break the symmetry, the so-called symmetry-protected topological phases. Examples of symmetry-protected phases include some topological superconductors and topological insulators, which are of widespread immediate interest because they show promise for use in the coming first generation of quantum electronics.

In the paper featured in today's issue of Science, Wen and collaborators reveal a new system which can, at last, successfully classify these symmetry-protected phases.

Using modern mathematics – specifically group cohomology theory and group super-cohomology theory – the researchers have constructed and classified the symmetry-protected phases in any number of dimensions and for any symmetries. Their new will provide insight about these quantum phases of matter, which may in turn increase our ability to design states of matter for use in or quantum computers.

This paper is a revealing look at the intricate and fascinating world of , and an important step toward a modern reclassification of all phases of .

Explore further: Synthesis of a new lean rare earth permanent magnetic compound superior to Nd2Fe14B

More information: Science paper: www.sciencemag.org/content/338/6114/1604.full

The current issue of Nature provides experimental confirmation of the existence of quantum spin liquids, one of the new states of matter that was theoretically predicted by Wen and collaborators

Wen's essay on the connections between condensed matter physics and cosmology

An introduction to understanding phases of matter based on symmetry

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Q-Star
2 / 5 (17) Dec 21, 2012
Oh my, this bad news indeed. If it wasn't enough that plasma had to compete with solids, liquids and gases (both hot and cold),,, now some miscreant seems to think there are 500 hundred phases of matter?

Where is Alfveen when we need him? Perhaps the electricians will step up to the plate to defend us from this heresy.
Q-Star
1.8 / 5 (13) Dec 21, 2012
P.S. Please don't tell the astrophysicists about this, they were annoying (and ignorant) before this,,, now they will be intolerable.
baudrunner
1 / 5 (7) Dec 21, 2012
Wen and collaborators reveal a new system which can, at last, successfully classify these symmetry-protected phases
That should read "at least", no?
Lurker2358
1.5 / 5 (16) Dec 21, 2012
When two particles are entangled, certain measurements performed on one of them immediately affect the other, no matter how far apart the particles are.


Why am I the only person who sees that there are only two possible conditions which would allow this?

1, Einstein's speed of light postulate is wrong (a very real possibility).

or

2, Observers simply don't get the fact that if two events have a common cause their metrics will be related. Conservation laws dictate a relationship between angular momenta, velocity, and other characteristics of particles or other events created at the same time. A measurement of particle A has not determined particle B's state. The measurement simply discovered a state which was always there.

Jeez, this entanglement thing is so hyped to it's become ridiculous.

Now if you don't agree with point 2, then point 1 must be true.

Why can't anyone see that?
Q-Star
3.2 / 5 (13) Dec 21, 2012
Now if you don't agree with point 2, then point 1 must be true.

Why can't anyone see that?


Because it might not be true?
DavidW
1.4 / 5 (10) Dec 21, 2012
Q-Star
2.9 / 5 (15) Dec 21, 2012
http://online.kitp.ucsb.edu/online/topomat11/gu/rm/flash.html


I don't know about anyone else. But when I see someone post a link without any context of what it might contain,,, I usually suspect that if they described the link no one would open it.

Meaning, you are probably hoping to get more views by hiding the fact that it is something that has previously gotten a negative response. Or no response.

God is so powerful that you must sneak him into the conversation?
RealityCheck
1 / 5 (9) Dec 21, 2012
Hi Lurker2358
Why am I the only person who sees that there are only two possible conditions which would allow this?

1, Einstein's speed of light postulate is wrong (a very real possibility).

or

2, Observers simply don't get the fact that if two events have a common cause their metrics will be related. Conservation laws dictate a relationship between angular momenta, velocity, and other characteristics of particles or other events created at the same time. A measurement of particle A has not determined particle B's state. The measurement simply discovered a state which was always there.

Jeez, this entanglement thing is so hyped to it's become ridiculous.


I have to agree with you here as well. It's much like my 'take' on this:

http://phys.org/n...dom.html

The 'correlation' is 'ongoing' from the word 'go' and is mediated continuously by the environment already 'shaped' by the generator of the entangled photons in the environment 'fields'.

Cheers!
eachus
3.3 / 5 (7) Dec 21, 2012
Why am I the only person who sees that there are only two possible conditions which would allow this?

1, Einstein's speed of light postulate is wrong (a very real possibility).

or

2, Observers simply don't get the fact that if two events...

Now if you don't agree with point 2, then point 1 must be true.

Why can't anyone see that?


Because we have studied the Bell inequalities and seen that they are violated. There is a nice description of the current state of the art wrt the Bell inequalities here: http://math.ucr.e...ity.html It is 16 years old now, but still pretty much describes the testing of Bell's inequalities. The tests are not perfect, but very convincing.

Is it possible that superluminal communication is possible, even though the Bell Inequalities are violated? Sure. A better way to state that is that physics needs a definition of causality that is consistent with both general relativity and QM. (Rather than neither.)
cantdrive85
1.8 / 5 (19) Dec 21, 2012
There is nothing but hot gas.
DavidW
1.5 / 5 (15) Dec 22, 2012
http://online.kit...ash.html


I don't know about anyone else. But when I see someone post a link without any context of what it might contain,,, I usually suspect that if they described the link no one would open it.

Meaning, you are probably hoping to get more views by hiding the fact that it is something that has previously gotten a negative response. Or no response.

God is so powerful that you must sneak him into the conversation?


You sound like you feel scared. Don't use a computer if you don't know how.
ValeriaT
1 / 5 (8) Dec 22, 2012
Herbertsmithite - a model of a two dimensional universe? String-net liquid model has become popular before few years. I do consider it a conceptual intermediate between topological string field (SFT) and loop quantum gravity (LQG) theories. In AWT it corresponds the fact, the density fluctuations inside of dense gases (typically condensing supercritical fluids) have character of mutually entangled strings and vortices.

The kagome lattice has its Coulomb force analogy in hexagonal Wigner crystals inside of Mott insulators, which are precursor of high-temperature superconductors. It illustrates the duality of electromagnetic and electrostatic interactions: whereas in the Wigner's lattice the charges of electrons cannot move at all, inside of kagomé lattice their spins reach the highest mobility under given conditions.
cantdrive85
2.4 / 5 (20) Dec 22, 2012
Being that we're 90 YEARS from the discovery and labeling of plasma and astrophysicists still can't grasp the difference between gas and plasma, we had better hope these states aren't applicable to any significant functions in the Universe. If they are, the best we can hope for the is they may incorporate these new states into their hypotheses in about 600 years or so.
jagdish_prasad_7127
1 / 5 (4) Dec 22, 2012
Oh my, this bad news indeed...
let me see the full article.

-Speedrefer.com
Whydening Gyre
1 / 5 (8) Dec 22, 2012
Homogeneity - in transition to dissipation phase...
Noumenon
2.4 / 5 (17) Dec 22, 2012
Homogeneity - in transition to dissipation phase...


That's gross.
Lurker2358
1.8 / 5 (10) Dec 22, 2012
A better way to state that is that physics needs a definition of causality that is consistent with both general relativity and QM. (Rather than neither.)


Do you see a problem yet?

When a theory starts to undermine the axioms and postulates it is based upon, either the theory has something wrong, or the axiom or postulate is wrong.

If causality is wrong then we can't make sense of anything anyway, as "prediction" is the primary test of the so-called "Scientific Method," and in fact in most cases it's the only test that is actually accepted.

QM entanglement experiments don't "predict" anything. They "post-dict," which means that technically they do not follow the "Scientific Method".

As for Relativity and the "no preferred reference frame" thing, try solving the planetary clock contradiction and the definition of kinetic energy contradiction.

http://www.physfo...ic=42752

and

http://www.physfo...ic=42788
Lurker2358
1.4 / 5 (9) Dec 22, 2012
The second thread is a "thought experiment" which proves it is NOT possible to construct a situation where real action is taking place, and all reference frames are "equally valid," because it can be shown that conservation of energy and conservation of momentum cannot both be maintained in frame A or B (which are the reverse of one another,) if they are maintained in frame C.

Both special relativity and General Relativity fail to explain this situation, as does Newtonian Dynamics, because the only reference frame which makes sense and conserves all constants, energy, and momenta is a "neutral" frame.

In the planetary clock contradiction, I show that if both observers start at the same location, as real space flight works, then the astronaut on board a relativistic rocket ship is forced to believe the Sun is 16 times as massive in order to explain how the Earth is held in orbit, and the Earth is 16 times as massive to explain how the Moon is in orbit, but he knows the "real" mass.
Lurker2358
1.4 / 5 (9) Dec 22, 2012
...but the contradiction lies in the fact that in the classic Einstein thought experiment, neither observer knows anything about the other observer's reference frame before observations are made.

In the real world, the space agency knows everything about the rocket ship, and any experiments designed on it, and the astronaut knows everything about the Earth, Sun, and Moon. Therefore it is nonsense for either observer to interpret the other reference frame as having relativistic mass or length contraction. This then forces the other observer to draw a different interpretation about time and the speed of light than what the normal interpretation of the formula (where both observers were ignorant) would produce.

This happens because we start with constants such as mass and length known by both observers. The normal thought experiment only produces length contraction and relativity of mass because those values are unknown to at least one observer, and therefore "open to interpretation".
Noumenon
3.1 / 5 (21) Dec 22, 2012
The correlation is ongoing from the word go and is mediated [..] by the environment [..] shaped by the generator of the entangled photons ....


You and Lurker have not discovered anything that was not already thought of. That was the obvious assumption initially, way back in the 1930's, that some sort of metric dictated the correlation between entangled states.

That would be considered a 'hidden variable'. Subsequently, is has been experimentally shown that this can not be correct, and that entangled systems must be considered as a Single system irrespective of distance or time between them.

....
Noumenon
2.9 / 5 (19) Dec 22, 2012
.....The concept of 'local realism' was a presumption based on intuitive concepts of space and time, which are not physical things. They are artifacts resulting from the mind operating on experience. The mind evolved these a-priori concepts at the macro scale, as a means of ordering experience.

In fact 'intuitive understanding' itself implies that these concepts are Presupposed and so, the 'form' in which reality is known.

But the 'conceptual form' is dependent upon mind, that is, the mechanics of the way the mind functions and orders experience for consciousness. Unconceptualized Reality itself, noumenal reality, has no use for this, ..it does not need to 'order experience' or ask such relations between things.

That QM is non-intuitive should come as no surprise, since the mind did not evolve at that scale, so could not possibly have ordering mechanisms that would 'make sense' of entanglement. The non-intutive nature of QM is an epistemological result, not a problem with theory.
Noumenon
2.6 / 5 (17) Dec 22, 2012
If causality is wrong then we can't make sense of anything anyway, as "prediction" is the primary test of the so-called "Scientific Method," and in fact in most cases it's the only test that is actually accepted.


It was shown quite some time ago by David Hume, that there is no analytic link between cause and effect,, .. rather, it is merely a matter of constant conjunction of events. This is why science is inductive.

Therefore it is not a physical structure, but a conceptual one. Causality is another a-priori intellectual form in which we order experience, that fails in consistency at the qm realm. Reality as it is in itself, is so connected that there are no 'cause' of 'effect', apart from being parsed in conceptualization.
Noumenon
2.6 / 5 (17) Dec 22, 2012
As for Relativity and the "no preferred reference frame" thing, try solving the planetary clock contradiction and the definition of kinetic energy contradiction. http://www.physfo...ic=42752


Regarding your post at physforums and the discrepancy between the number of orbits,.. when the observations are made, the ship is moving away from the earth, but equivalently the earth is moving away from the ship. The earth sun system can be thought of as a big clock, which according to the ship is moving away at great speed, so slows down. There is no paradox, they both agree.
mrcoldheart
5 / 5 (4) Dec 22, 2012

Now if you don't agree with point 2, then point 1 must be true.

Why can't anyone see that?


Because quantum entanglement doesn't violate Einstein's speed of information rule.

Why spend so much time trying to prove Einstein wrong when you haven't taken the time to fully understand the difference between quantum mechanics and special relativity.
ValeriaT
1 / 5 (4) Dec 22, 2012
The quantum mechanics (QM) describes the world, which is less or more driven with superluminal longitudinal waves of vacuum (aka scalar waves). If we would live at the water surface like the water striders and if we could observe it with its transverse waves only, then the phenomena mediated with longitudinal waves would appear just in the same way, in which the QM describes. The motion of objects would appear less or more correlated each other. The longitudinal wave character of quantum mechanics is even more apparent, if we illustrate quantum waves with their particle analogy. The quantum correlation simply requires the superluminal energy transfer to work, without it the QM would be unthinkable.
RealityCheck
1 / 5 (8) Dec 22, 2012
You and Lurker have not discovered anything that was not already thought of. That was the obvious assumption initially, way back in the 1930's, that some sort of metric dictated the correlation between entangled states.

That would be considered a 'hidden variable'. Subsequently, is has been experimentally shown that this can not be correct, and that ENTANGLED SYSTEMS MUST BE CONSIDERED AS A SINGLE SYSTEM IRRESPECTIVE OF distance or time between them.

....


Basically what I said. The pre-existing environment is shaped and photons behave accordingly as 'paired feature' from common 'origin' having opposite/complementary properties intrinsically and with respect to extrinsic environment [as a single 'system'] that has been there all along and 'shaped' by the entangling event and ongoing propagating properties in 'complementarity' states. Cheers!
Noumenon
2.8 / 5 (18) Dec 22, 2012
That would be a hidden variable, which has been disproved experimentally. Cheers!
RealityCheck
1 / 5 (7) Dec 22, 2012
That would be a hidden variable, which has been disproved experimentally. Cheers!


But the above article positing all these heretofore unsuspected 'string-net of light and electrons" and other kinds of "topologically ordered matter" extends the possibility that space is replete with several more-fundamental 'layers' of such networks/fields which our theories/experiments cannot/have not yet touched upon. So the 'disproofs' (or more correctly, the 'falsifications') of 'hidden variable' hypotheses may be not as 'final' as you think.

And my earlier link to that other 'correlation' between photons/outlets 'pairings' as being continually communicated between the phonic features/paths/fields along the way to thier 'correlated exits' also makes claims of 'absolute disproof' of hidden variables a little premature....

http://phys.org/n...dom.html

In any case, there is more at play than we know. So everything is back on the table now. Cheers!
RealityCheck
1 / 5 (6) Dec 22, 2012
Sorry: the above link was shortened before posting, so it won't be valid for the system. It should have been posted in my postbox in full, and shortened by the system, thus....http://phys.org/n...dom.html
Job001
1 / 5 (5) Dec 22, 2012
...but the contradiction lies in the fact that in the classic Einstein thought experiment.
This then forces the other observer to draw a different interpretation about time.

"Real" time does not exist except as a modeling connivence and thus figment of human imagination, so give it up. The causality issue also goes away without "real" time. Since we cannot see, feel, hear, taste, measure, construct, destroy, or demonstrate time exists, why do you believe in such nonsense? Events we define thus definitionally exist and like objects with nothing in-between, there is nothing in-between definitional events. Therefore time is a nothing between events non-thing and does not exist, no matter how strong our irrational need to believe in time may be.
barakn
2.3 / 5 (3) Dec 23, 2012
Can Q-Star, frajo, Shabs42, FrankHerbert, jsdarkdestruction, atomsk, or lite explain why they dumped on DavidW when he posted a perfectly legitimate, topical link and then tried to defend himself against Q-star's vicious and pointless attack? Just one dummy following the other, I suppose.
Tausch
1 / 5 (5) Dec 23, 2012
Perhaps rating can only be posted when coupled with feedback.
That can be accomplished with a change in code for this website.

Rating alone is insufficient feedback.
The site owners are aware of this.
Noumenon
2.3 / 5 (15) Dec 23, 2012
Perhaps rating can only be posted when coupled with feedback.
That can be accomplished with a change in code for this website.

Rating alone is insufficient feedback.
The site owners are aware of this.


I have sent many emails to the mods asking to implement this idea. They don't respond, so my guess is they don't know how.
Noumenon
2.5 / 5 (16) Dec 23, 2012
Can Q-Star, frajo, Shabs42, FrankHerbert, jsdarkdestruction, atomsk, or lite explain why they dumped on DavidW when he posted a perfectly legitimate, topical link and then tried to defend himself against Q-star's vicious and pointless attack? Just one dummy following the other, I suppose. - Barakn


Would you like to explain the following odd and emotional response you made to my legitimate and reasoned post that homosexuality is an abnormal defect, in the other thread?....

Ultimately Noumenon's posts are interesting, as we can see how the bigot twists science into pseudoscience to further his/her/its faith-based agenda, and perhaps is venting to relieve the pressure of fear, doubt, and self-loathing. - barakn


I don't have an agenda, nor do I believe in god, just speaking factually and logically,.. then YOU dump in with your emotional whining about it. Hypocrite?
frajo
5 / 5 (3) Dec 23, 2012
Can Q-Star, frajo, Shabs42, FrankHerbert, jsdarkdestruction, atomsk, or lite explain why they dumped on DavidW when he posted a perfectly legitimate, topical link and then tried to defend himself against Q-star's vicious and pointless attack?

Thanks for asking.
First, I don't like context-free links like that one DavidW posted. I think it's impolite to give no hint what the link is about.
If you consider the link to be perfectly legitimate and topical you are giving an a-posteriori assessment that is not possible to obtain a priori.

Second, DavidW's ridicule of me being scared by unexpectedly having been tricked into seeing cruelty and violence is cynical. Moreover is his implied correlation of being scared and lack of knowledge to handle a computer not only illogical but also unsensible and hostile.

DavidW will have some work to do before the negative impact of his two postings in this thread is going to be neutralized.

Of course, I speak only for myself.
Foolish1
1 / 5 (2) Dec 27, 2012
2, Observers simply don't get the fact that if two events have a common cause their metrics will be related. Conservation laws dictate a relationship between angular momenta, velocity, and other characteristics of particles or other events created at the same time. A measurement of particle A has not determined particle B's state. The measurement simply discovered a state which was always there.

In the matrix this wavefunction thing reflects the transaction semantics upon which all computation is realized.

Your error is in expecting the metal upon which the matrix runs to represent anything recongizable to you as reality.

~neo
reid barnes
1.8 / 5 (5) Jan 23, 2013
Will relativity serve up 500 phases of matter in any number of dimensions while we ignore plasma physics? Are we clinging to relativistic space-time gravitational concepts that distort reality? Now "group super-cohomology' theory has served up "symmetry-protected phases" in any number of dimensions. Before this, relativity related cosmology and atomic theory generated alarming infinities, which were produced in non-Euclidean geometry, which became the geometry of Einstein's general theory of relativity and infused the theory of the electron with extra dimensions. At the root has been a misconception spawned by flawed non-Euclidean geometry in the theory of relativity.