MIT discovers a new state of matter, a new kind of magnetism

Solid materials are much more complex than single atoms and support several types of multiple particle states. One noteworthy example is the Cooper pairs that result in conventional superconductivity. Spin-liquid states are also multi particle states with the interesting property that they exhibit entanglement between the magnetic moments of the atoms, and it is this entanglement that makes them intersting for quantum informatics because it can be used fo form qbits.

An intersting feature of the Herbertsmitihe crystals that were used for the study is that have a geometric structure that frustrates the ordering of the magnetic moments (or spins) of the atoms. The magnetic moment will try to align in opposite directions but the crystal structure has three magnetic moments in each unit cell and therefore only two of them can allign in an energetically favorable state while the last one is unable to moove into a stable equlibrium. Since there is no distinction between the three magnetic moments per se, the frustration is spread across the whole solid structure and a "large" entangled stage is formed.

Because these states are not locallized they are not constrained by the atomic properties of the cryatal atoms and therefore they are allowed to accept excitations at a continous range of engergies rather than the discrete ones that we normally see. It is a little bit similar to free electrons in metals. They can also be excited by a continous range of energies because they are free to move within the material.

An important thing to note, however, is that these experiments were carried out at 1.6 K, where thermal fluctuations play a very small role compared to room temperature. Therefore it is not likely that this effect will be portable to regular electronics devices. More likely quantum informatics applications include massive server like facilities that has the infrastructure to cool the devices down to cryogenic temperatures and the best we can hope for in terms of avaliability is some kind of cloud service.

There is an interesting press release at Phys.org: http://phys.org/news/2012-12-newly-quantum-liquid-beauty-sim...

Edit: Corrected BSC pairs to Cooper pairs, and added a bit more information after reading the actual paper which is available for those sitting behind a pay wall: http://www.nature.com/nature/journal/v492/n7429/full/nature1...

You may want to read about the discovery that earned three researchers the 1998 Nobel prize then.

http://en.wikipedia.org/wiki/Fractional_quantum_Hall_effect

Though, you usually need to take graduate level solid state course to get to understanding it.

They aren't excitations of individual electrons, but of the system as a whole. I'd assume they're some sort of quasi-particle, though this isn't really my field.

http://en.wikipedia.org/wiki/Quasiparticle

http://en.wikipedia.org/wiki/Spin_liquid#Excitations

There is a good chance that MIT's press release was written , outlined, or edited by the actual scientists who did the research. I recall working in OpenAcess publishing and we would inform the author's when their paper was published so they could time the press release.

More informative indeed, but still with the unexplained "There is no theory that describes everything that we’re seeing." What are they seeing that no theory describes?

Most things below the atomic level occur in quantized form, meaning variables that hop between discrete states. For example, energy radiated by electrons falling into a lower orbit is exactly equal to the difference in energy between the two orbits. Or take sub-atomic particles that have properties like spin, this also occurs in discrete steps. What this means in the context of these new magnets though I'm not sure. I seem to recall a paper where fractionalized spin states where hypothesized but I can't find it right now.

The top physics kids in the US tend to get picked up by financial (or some other industry) firms because they're really really sharp because making 200k sounds much better than making 30k. This means that the kids who go into physics are doing it because they truly love the subject but it also means that we have a much smaller percentage of kids going into graduate studies than otherwise. This, combined with the fact that many countries are rapidly industrializing and newly able to support an academic class means that lots of international students are applying to Harvard/MIT/Stanford/etc where some of the best science in the world is happening. Some of the foreign kids go back, some stay here. It really depends. As for makeup? probably 40%-50% of my entering cohort was foreign and probably 60% of the foreigners were asian. That's not really a bad thing though. They're brilliant scientists and it's truly a pleasure to collaborate with them and everyone else in my programme as well.

Disclaimer, I'm a physics PhD student at Harvard and go to seminars a lot with kids from MIT.

to me, Young Lee sounds more Korean than Chinese :)

Entanglement alone can't be used to transmit information. If this is the first time long-range entanglement has been possible then the communications advances they're talking about would include anything that requires parties to share entanglement over a distance. So quantum encryption, key exchange, superdense coding (is that even likely to be useful?) etc. Someone who knows what they're talking about want to weigh in here?

Entangled particles communicate instantaneously through space. That is to say, communication faster than the speed of light. This was actually one of the reasons that Einstein did not want to accept quantum theory. In fact, he proposed quantum entanglement as an argument against the validity of quantum theory. According to quantum theory, transfer of information faster than the speed of light should be possible (via quantum entanglement). Therefore, quantum theory was incorrect/incomplete- that was Einstein's reasoning.

There would still have to be an entanglement step. The photons need to be coupled. This is currently accomplished by a laser across long distances. I suppose that in this sense there is a latency at the speed of light to add new particles. But once the photons have been entangled they can communicate instantaneously.

"In Quantum entanglement, part of the transfer happens instantaneously. Repeated experiments have verified that this works even when the measurements are performed more quickly than light could travel between the sites of measurement" http://en.wikipedia.org/wiki/Quantum_entanglement

from the Nature article preview: "The experimental realization of quantum spin liquids is a long-sought goal in physics, as they represent new states of matter." http://www.nature.com/nature/journal/v492/n7429/full/nature1...

Catagorizing new matter/energy phemenon as a state of matter just confuses the understanding. If the particle is simultaneously exhibiting qualities of liquid and a solid, it means a shift in thinking is required.

Iron is solid, but that doesn't mean we should group it with other things that are hard. The other hard object might be hard for a completely different quantum mechanical reason.