Researchers find what may be a new state of matter

[Ace Pace]

Ars

Think way back to elementary or primary school, somewhere around third-grade physical science, when you first learned about the various states of matter. At the time you were undoubtedly told that there were three states of matter: solid, liquid, and gas. Solid is where the atoms are tightly packed into some arrangement and vibrate in place; liquids have more freedom of motion and vibration, allowing them to take on any bulk shape; gas molecules had near complete freedom of motion and rarely saw another molecule. Perhaps later you learned about plasma (molecules where the electrons have been completely stripped from the nucleus) as a fourth state, but for most people their education regarding states of matter ends around there. New work by a pair of theoretical physicists studying an odd quantum mechanical effect may reveal a new state of matter, and if their model is shown to be accurate, it will completely change how we view the universe.

Quasi-particles

About ten years ago the Nobel prize in physics went to a team for their discovery of what they termed quasi-particles. These were particles that seemed to have a fractional charge, something that should not be possible according to physics. They were seen in an experiment where electrons moved across an interface between two semiconducting materials, and they behaved as though they did not have an integer charge on them. This phenomena, termed the fractional quantum Hall effect (FQHE), suggested that electrons are NOT a fundamental particle in our universe. Were this to be true, much of physics would need to be rethought. However, it was found that this observed fractional charge was due to the positions of a group of electrons near one another. This positioning gave the illusion of a fractional charge. The charge on the electron was correct and physics could rest easy.

This idea of quasi-particles clearly intrigued people; Xiao-Gang Wen at MIT and Micheal Levin at Harvard University began to look at this in further detail. They felt that the electrons in this arrangement could represent a new state of matter. According to Wen, when you look at the electrons in the FQHE system, they appear in a random position similar to a liquid. However, the electrons move in a well-correlated manner, as if they were all entangled. Wen speculated that this potentially new state of matter is one where quantum entanglement is a basic property.

String-nets



Using this idea, Wen and Levin postulated something incredible: what if electrons were not fundamental particles, but merely the ends of long strings of other "true" fundamental particles? With this idea, the pair developed a new model for matter where it was made up of these strings woven together to form what they dubbed "string-nets." Developing and running computer simulations of this model showed that it gave rise to both conventional particles as well as the quasi-particles, those which carried a fractional charge that began this whole adventure. Then they discovered something completely unexpected.

As the "string-net" vibrated, it produced waves as any vibrating net would, but the pair soon realized that the waves being emitted by the "string-net" behaved exactly as they would according to Maxwell's equations—the set of equations that describe how electromagnetic radiation behaves! As Wen himself says "A hundred and fifty years after Maxwell wrote them down, here they emerged by accident." While a huge success, the model didn't stop there: Wen and Levin showed that the model could give rise to quarks—which make up protons and neutrons—as well as the force particles: gluons and W and Z bosons! From here, the researchers made a huge leap to suggest that this model may be capable of explaining the structure of the universe. If it can explain how both light and matter can be formed from the vacuum of space, perhaps they are onto something big. (Prof. Wen's lecture on this topic is available online.)

At this point any good scientist will be reading with a grain of salt; it isn't every day that someone suggests that what physics considers as the basic building blocks of the universe are called into question. Many did. According to Michael Freedman, winner of the Fields medal in 1986 and quantum computing expert at Microsoft, "Wen and Levin's theory is really beautiful stuff. I admire their approach, which is to be suspicious of anything–electrons, photons, Maxwell's equations–that everyone else accepts as fundamental."

A very unusual mineral

While this could have been relegated to wherever science puts the many other theories that have tried to explain the universe, this idea received a big boost from an unlikely source. In 1972 geologists unearthed a new type of mineral in Chile; this mineral, now known as herbertsmithite, has a very unusual property: its electrons are arranged in a triangular lattice. This is atypical since electrons usually line up in pairs so they can have the opposite spin as their nearest neighbor. In a triangle, two neighbors will be forced to have the same spin. According to Wen and Levin, this ternary electron system would be a string-net liquid, their new state of matter.

Recently another group at MIT who were aware of Wen and Levin's theory started trying to synthesize this material, herbertsmithite, without defects so it could be studied in detail. After achieving the goal of growing the mineral, they began to characterize it and found that it was unlike many other minerals on Earth. Most minerals exhibit what is called magnetic ordering—where the electron spins in a lattice line up. In the synthesized material no such ordering was found no matter how cold they made the crystal. Even at a fraction of a degree Kelvin, no magnetic order appeared. The team also measured the heat capacity of the material; often this will change below a certain temperature due to a structural change in the material. Again, no such change was found even down to incredibly low temperatures. According to Y. S. Lee, the MIT professor who oversees the lab where the herbertsmithite was synthesized, "We could have created something in the lab that nobody has seen before."

Further studies into the details of the possible entanglement properties of this material are being undertaken now. The team, led by Prof. Lee, is firing neutrons into the material to see if there is any long-range correlation in the motion of the electrons, indicating some degree of entanglement. While these are both radical concepts—one challenges the very fundamentals of physics while the other suggesting a type of material never before studied—the experiments and theories are in the early stages. Even if they do not pan out, it is worth noting that there are many other groups around the world looking for new states of matter every day. Michael Freedman rightly notes that often people think new states of matter only occur in the high temperatures and energies of particle accelerators which, as he puts, "are just recreating conditions after the big bang and repeating experiments that are old hat for the universe." New materials and theories are being discovered all the time.

[Edi]

Well, that was interesting. Not something you see everyday.

[CaptainChewbacca]

A goddamn naturally occurring fourth state of matter would change quite a bit about what we know to be certain in the universe.

I actually got to hold a sample, once, in a geology workshop.

[Admiral Valdemar]

A goddamn naturally occurring fourth state of matter would change quite a bit about what we know to be certain in the universe.

I actually got to hold a sample, once, in a geology workshop.

There already is a natural fourth state of matter, or did you clearly forget plasma that happens to be driving the big energy source in the sky we depend on? A natural fifth state of matter would be curious and bring the total states to six when you include BECs.

[CaptainChewbacca]

It was a typo, of course I know plasma. I didn't know BECs were an 'official' state of matter, though.

[Kittie Rose]

So are they saying leptons have internal structure now?

[Admiral Valdemar]

It was a typo, of course I know plasma. I didn't know BECs were an 'official' state of matter, though.

It doesn't act like any other state of matter, ergo, it's different. If solid moving to liquid can be classed as a phase transition, then so can solid to solid-with-all-quanta-on-same-energy-level.

[Kittie Rose]

What exactly should we define as a state of matter, though? Isn't this a different kind of state of matter all together?

All of the existing ones are basically just a scale of "Looseness" from Solid to Plasma. Other "ways of being" for matter would surely be on a different scale, so we should signify it as such?

Or you could get really specific and inclusive, and consider Jelly a state of matter (see: Science of Discworld).

[CaptainChewbacca]

What exactly should we define as a state of matter, though? Isn't this a different kind of state of matter all together?

All of the existing ones are basically just a scale of "Looseness" from Solid to Plasma. Other "ways of being" for matter would surely be on a different scale, so we should signify it as such?

Or you could get really specific and inclusive, and consider Jelly a state of matter (see: Science of Discworld).

States of matter seem to be defined by electron movement, and the triangular arrangement in the 'nets' discovered would definitely qualify it as being separate.

[Spin Echo]

Or you could get really specific and inclusive, and consider Jelly a state of matter (see: Science of Discworld).

Jelly falls under the category of complex materials, materials that exhibit both solid like and liquid like characterisitics. Depending on a complex materials properties' (shear-thinning, shear thickening, thixotropic, etc) and the time scale at which you observe it will determine if it's considered solid or liquid.

Think Silly Putty. You can roll it up into a ball and put it on the table. For a while, it will hold its shape and appear solid. Given enough time though, the putty will slowly sag and spread out on the table. Depending on how long you observed it, you would either say the putty was a solid or a liquid.

[Kittie Rose]

What about Mercury, is it considered the same?

[Elaro]

What about Mercury, is it considered the same?

Mercury the element is liquid at room temperature.

[Spin Echo]

What about Mercury, is it considered the same?

No. Mercury is a not a complex material. The reason it will form little beads when it's spilled it because mercury has very high surface tension. What makes something a complex fluid is that's behaviour changes depending on whether its oberserved over long or short periods of time or whether it's behaviour depends on the force applied.

A good example is cornstarch in water. When you apply a force very quickly, it acts as a solid and resists deformation. However, apply a force slowly, and it deforms like a liquid. No matter how slowly or quickly you apply a force to mercury, it will respond in the same manner. No matter how long of a time you observe mercury, it will only show liquid like or solid like behaviour depending on the state its in.

[Admiral Valdemar]

Jelly would be within the solidus/liquidus spectrum of transition, where a solid is approaching a liquid and vice versa. They are simply variations on two already known states. Plasma and BECs are really quite different, more than just how much energy the molecules have since one requires ionisation and free electrons and the other is a state with practically no net temperature whereby all atoms fall into a single energy state.

[Tahlan]

Has anyone thought about linking this new matter to "dark matter." Here's the link to the SDN thread. Dark Matter/Energy

[Spin Echo]

Jelly would be within the solidus/liquidus spectrum of transition, where a solid is approaching a liquid and vice versa. They are simply variations on two already known states. Plasma and BECs are really quite different, more than just how much energy the molecules have since one requires ionisation and free electrons and the other is a state with practically no net temperature whereby all atoms fall into a single energy state.

To say that jelly is in a state of transition is not an acurate description. Jelly is a gel type colloid where you have a liquid medium dispersed throughout a solid medium. Both phases are simueltaneously present and by heating the jelly, you won't get parts of the solid phase changing to liquid or vice versa with cooling.

But you're right that jelly is really just a variation on known states.

[Admiral Valdemar]

I've always wondered, if there a way to discern how solid/liquid a product is such as toothpaste or jelly other than viscosity? It would seem that toothpaste was more fluid than a set jelly.

[Spin Echo]

I've always wondered, if there a way to discern how solid/liquid a product is such as toothpaste or jelly other than viscosity? It would seem that toothpaste was more fluid than a set jelly.

Rheology is the branch of science devoted to determining how liquid like and how solid like materials are. To determine how liquid like jelly is compared to toothpaste, you'd put into a sample into a rheometer. You could then perform an experiment called a frequency sweep. The rheometer applies tiny oscillatory deformations of fixed amplitude upon the sample. The frequency of these deformations are ramped.

The rheometer measures here two parameters, G' the storage modulus and G'' the loss modulus over the range of frequencies. The storage modulus (how much energy from the deformation is stored) is a measure of how solid a material is and the loss modulus (how much energy is lost into the system) is how liquid like it is. When you get the storage modulus dominating the loss modulus, it's said to be solid like. The greater the storage modulus over the loss modulus, the more solid like it is. Vice versa with when the loss modulus dominates the storage modulus, it's considered liquid like.

[Admiral Valdemar]

Interesting. Reminds me of seismic readings taken by air guns and the like to determine crust depth and composition etc. Only with jelly.

[kheegster]

Has anyone thought about linking this new matter to "dark matter." Here's the link to the SDN thread. Dark Matter/Energy

No, because different states of matter is just the same type of matter behaving in different ways. E.g. water, ice and steam are all composed of hydrogen and oxygen atoms even though those are three different phases of matter.

Dark matter is something different entirely. Not only does it not interact at all with electromagnetic waves (i.e. light), it does not interact with baryonic matter since most interactions between matter outside of stars occur via electromagnetic interactions. In addition, it cannot be baryonic matter (i.e. neutrons and protons) since it is in excess of what is predicted from Big Bang nucleosynthesis.

[Il Saggiatore]

I just hate press releases!

Nit-pick #1: what physicists call "quasi-particles" has been introduced decades ago by Landau with the Fermi liquid theory (gas of interacting fermions).
An example are holes in semiconductors.

Nit-pick #2: in the Fractional Quantum Hall Effect we have one electron coupled to a number of quanta of magnetic flux, and the system can be described in terms of "particles" with fractional charge.
But that does not mean that there are new elementary particles in that effect. And I doubt that physicists ever seriously thought that they were splitting electrons using magnetic fields.

Nit-pick #3: research on spins arranged on triangular lattices is also decades old.
A quick Google search shows that this mineral has the spins arranged as a Kagome' lattice (Physics Today link).

Nit-pick #4: magnetic systems have shown a boat-load of phases, so all this talk about new states of matter is just PR sales pitch.
Personally, graphene is cooler.

(Alright, I never particularly liked magnetism in condensed matter. It gives me headaches.)

[Thinkmarble]

States of matter seem to be defined by electron movement, and the triangular arrangement in the 'nets' discovered would definitely qualify it as being separate.

Phases of matter are defined by the behaviour of state variables. If the nth derivative of a state variables is discontinuos then you got a state change/phase transition of nth order.
Commonly known phase transitions/phases (eg.liquid to solid) are phase transition of the 1st order

[wautd]

Ars

A very unusual mineral

While this could have been relegated to wherever science puts the many other theories that have tried to explain the universe, this idea received a big boost from an unlikely source. In 1972 geologists unearthed a new type of mineral in Chile; this mineral, now known as herbertsmithite, has a very unusual property: its electrons are arranged in a triangular lattice. This is atypical since electrons usually line up in pairs so they can have the opposite spin as their nearest neighbor. In a triangle, two neighbors will be forced to have the same spin. According to Wen and Levin, this ternary electron system would be a string-net liquid, their new state of matter.

Guess it was too soon to name it tiberium.

Interesting article

[Winston Blake]

New work by a pair of theoretical physicists studying an odd quantum mechanical effect may reveal a new state of matter, and if their model is shown to be accurate, it will completely change how we view the universe.

I hate sensationalist bullshit like this. It'll extend our understanding. Maybe competing theories on the bleeding edge will get settled. It may well change the nitty-gritty details on how we view the universe. It is not going to fucking 'completely change' everything.

Quasi-particles

About ten years ago the Nobel prize in physics went to a team for their discovery of what they termed quasi-particles. These were particles that seemed to have a fractional charge, something that should not be possible according to physics.

What the fuck? Quarks have fractional charge and that's been around for ages. I guess you can't expect much more than an out-of-context copy-paste form somebody who uses phrases like 'according to physics'.

A goddamn naturally occurring fourth state of matter would change quite a bit about what we know to be certain in the universe.

I actually got to hold a sample, once, in a geology workshop.

There already is a natural fourth state of matter, or did you clearly forget plasma that happens to be driving the big energy source in the sky we depend on? A natural fifth state of matter would be curious and bring the total states to six when you include BECs.

There's lots of phases. Superconductors undergo a phase change when they hit critical temperature. Helium changes phase when it becomes superfluid. I think paramagnetic oxygen does. IIRC liquid crystals under stimulation undergo a phase change too. In fact, considering the crystal structure of this special mineral to be a new phase is kinda similar to liquid crystals.

The big four, solid/liquid/gas/plasma are special since with enough heat transfer you can make them from just about anything (helium above excepted). BECs don't fit this; only half the elements have bosonic nuclei. They should be put together with the fermion version and just called, I don't know, condensates. A QGP in a particle accelerator (as hinted in the article) is a step in the other direction - way hotter than any regular plasma.

So that's, what, 10 phases already? Collapsed stars probably have bizarro way-over-my-head ones.

[metavac]

States of matter seem to be defined by electron movement, and the triangular arrangement in the 'nets' discovered would definitely qualify it as being separate.

Phases of matter are defined by the behaviour of state variables. If the nth derivative of a state variables is discontinuos then you got a state change/phase transition of nth order.
Commonly known phase transitions/phases (eg.liquid to solid) are phase transition of the 1st order

More generally, a phase transition occurs at any boundary where symmetry breaks in a thermodynamic or quantum variable. Within a phase, symmetric transformations of properties are smooth (infinitely differentiable). At the transition boundary, there is a discontinuity which breaks this symmetry.