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MIT Physicists Create New Form of Matter
Ninwa writes "According to the MIT news office the folks in their labs have really outdone themselves this time, they've
created a new form of matter. The post states, 'They have become the first to create a new type of matter, a gas of atoms that shows high-temperature superfluidity.' It has been said that this could solve the mysteries in superconductivity."
My favorite one - Neutronium
The Raven
McFly?
If you start a superfluid rotating and it flows without friction, will it ever stop?
Doesn't exist.
If you start a current flowing in a superconducting loop and there's no electrical resistance, won't it flow forever?
Doesn't exist.
In order to achieve 50 nanokelvin, you have to use "laser and evaporative cooling techniques". The article failed to explain how that worked, so here it goes. Temperature is essentially a measurement of the average kinetic energy (energy of motion) of a bunch of atoms/molecules. So when you're working with small samples of gas, cooling it down is essentially slowing it down. In laser cooling, a laser with a material-specific frequency is shown towards a sample of gas which is moving toward it. The photons striking the gas are absorbed and then re-emitted. Some of the kinetic energy goes into the re-emitted photons and therefore the gas sample cools. Evaporative cooling is similar to what you'd expect. The gas sample is placed into an inverted "cone". (Note: Not a physical container, but made of lasers and magnetic fields.) The faster moving atoms/molecules move upwards and out while the slower moving ones settle to the bottom. The end result is a supercooled gas at the bottom of your "cone". I am not a physicist, but this is how it was explained to me by one of Ketterle's grad students. I went on a tour of the lab a week before this discovery was made. Surprisingly, it was a sweltering 90 degrees in the room.
Read further - immediately after that comment:
"Scaled up to the density of electrons in a metal, the superfluid transition temperature in atomic gases would be higher than room temperature."
So maybe it could actually be used.
Explanation of what "funky" means... The wave-functions of the particles start collapsing, essentially describing one giant particle. You are unable to distinguish one particle from the other, since they have the same wave-function - they collapse into the lowest possible quantum state.
I thought gasesous superfluids (Bose-Einstein Condensate) had already been created in 1995:
Bose-Einstein condensate is a gaseous superfluid phase formed by atoms cooled to temperatures very near to absolute zero. The first such condensate was produced by Eric Cornell and Carl Wieman in 1995 at the University of Colorado at Boulder, using a gas of rubidium atoms cooled to 170 nanokelvins (nK). Under such conditions, a large fraction of the atoms collapse into the lowest quantum state, producing a superfluid.
Wikipedia article
Vivin Suresh Paliath
http://vivin.net
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Matter can exist in four phases (or states), solid, liquid, gas, and plasma plus a few other extreme phases, like critical fluids and degenerate gases.
Religion for nerds. Stuff that really matters
First of all, as previously mentioned, 50 nanoKelvin, i.e. 0.000000050 K degrees is nowhere close to room temperature. The definition of temperature is what they are playing with to call this "hot", saying the density is low.
Otherwise I think even superconductor rings lose energy over time, because they have a magnetic field, which can induce current in moving conducturs, which in turn generates an opposing magnetic field that generates a back emf slowing the superconducting electrons down. That's how you take back the electrical energy stored in them, but that's also how anything conducting moving in its magnetic field "steals" energy and loses it through ohmic resistance.
Even mechanical superfluids interact with their environment, if by nothing else, by electromagnetic radiation, to the nearest wall, which then conducts the heat/cold away. (Unless of course you have full thermal death in the Universe, everything being at the same exact temperature, and at this temperature your thing is superfluid.)
Therefore, because of interactions with the imperfect/lossy environment, perfect perpetuum mobile things only exist in an environment that's:
a) either perfectly isolated,
b) or perfectly nonlossy itself
In this world nothing macroscopic is perpetuum mobile, you can only talk about close enough, such as using good bearings on a 10 ton cylinder spinning in a vacuum chamber, where your losses could be made, well, negligible for a decade. Tough it'd be interesting to see these superfluids used as bearing lubricants.
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from the article
"The team observed fermionic superfluidity in the lithium-6 isotope comprising three protons, three neutrons and three electrons. Since the total number of constituents is odd, lithium-6 is a fermion."
So this is a fermi condensate, and not a boson condensate.
I have never let my schooling interfere with my education. - Mark Twain
Well, it seems that it depends who you ask. Particle physicists will say that matter can be split into elementary particles. These particles can be divided into two categories, fermions and bosons. Fermions are all the elementary particles that are building blocks of nature e.g electrons are fermions, quarks are fermions etc... They have a half integral spin. Bosons are all the carriers of forces. Photon is the carrier of the electromagnetic force and has integral spin. Hence it is a boson. The idea is that these two different categories of particles have a nice property. Fermions obey the Fermi - Dirac statistics while bosons obey the Bose - Einstein statistics. What this means is that an infinite amount of bosons can coexist in the same quantum state while this does not apply to fermions ( technicallities omitted ). This is known as Pauli's exclusion principle. That is why an infinite amount of bosons can add up and create a macroscopic force and why all matter has not condensed to a drop of infinite density. Neat huh?
Now, particle physicists will say that all these fermions and bosons and their combinations ( you can have baryons and mesons etc etc - doesn't matter what these are ) are "ordinary matter". Electron - Electron pairs ( Coopper pairs ) that are formed in superconductors ( and make the phenomenon possible ) or whatever weird combination of ferminos and bosons you come up with are called "states of matter" or something like that but not a new form of matter. You have ordinary matter there, part of the so called Standard Model. It is just elecrtrons and atoms and so on but combined in a different way and with different external conditions ( like pressure and temperature ). So they are just different states of matter.
There are some cosmology related problems these days. One of these is that the ordinary matter that experts can see with their telescopes amounts to a tiny fraction of the matter that they calculate there is out there. Let's say 5% ( I do not really remember the exact number, but it is quite small ). What is the nature of the rest 95%? There are some speculations but what experts say is that "it is a new form of matter". No protons, no electrons, no neutrinos. Nothing that can emit radiation ( that's why the name dark matter ). Fascinating... No need to say more about this, interesting stuff however, you can google it or have a look at wikipedia for dark matter, cosmological constant and each page will bring another and so on.
The conclusion: Not a new form of matter but a new state of it. And by the way, superfluidity is a phenomenon discovered around the '30s. Certainly there are many interesting things about it and is not a "job done" however keep in mind that laboratories are also very aware of public relations. If this is a breakthrough or an important discovery, experts will decide and time will tell.
Cheers!
It's a fermionic condensate. Not Bose-Einstein condensate. The gas is fermionic (half integer spin) and behaves very very differently than a bosonic condensate (integer spin). Namely, bosons are not subject to the Pauli exclusion principle (exchange forces, yadda yadda).
As mentioned in another post, this is a Fermi condensate, where Fermions are "those things that aren't Bosons". Fundamentally different and potentially nifty.
No, lithium-6 is a fermion, not a boson, so it's called a Fermion condensate. It's been theorized for years but apparently no one has actually succeeded in creating it until now?
A small correction on your thing about nanotubes: the limiting factor in current nanotube composites is not the weakness of inter-nanotube bonds, but the fact that nanotube composites do not even use these weak bonds well enough. Spinning fibers of dense, aligned nanotubes is very difficult.
Of course, longer nanotubes would help, as you suggest, but I'm saying that even current nanotube production techniques could theoretically produce some extremely high tensile strength fibers (they can already claim the highest toughness).
Bose-Einstein Condensate is considered the fifth major form of matter.
Neutron stars have superfluid cores. Superfluidity isn't quite the same as superconductivity, but it's related. See http://imagine.gsfc.nasa.gov/docs/ask_astro/answer s/970213.html, for example.
-- Steve
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In fact, neutron stars are thought to have superconducting (and superfluid) cores. They also may be superconductors of the strong nuclear force ("color superconductors").
On a related note, "Exploring Superconductors and Neutron Stars on a Desktop using Ultracold Fermi Gases".
Very nice summary, thank you sir. Just a little of my understanding as a supplementary: superfluidity, closely related to superconductivity, has a lot to do with long range order of the matter (coherence, phase-correlation and all that), and as we all know, lower temperatures tend to produce more ordered states, and that's why both phenomena typically only present at low temperatures. Particularly, superfluidity was pretty much limited to liquid helium 3 and 4, and liquid hydrogen. That's why this discovery is actually a big deal. Before reading the related paper (hey, it's /.), I'd guess for now that it has something to do with ions pairing that make them effectively bozons, which would definitely be interesting for physicists, but calling it a "new matter" is more marketing than science -- IMHO at least. But what would an AC know anyway?
* above was written with extremely non-professional terminology, posted as AC so my professor will not shoot me on sight.
For more details, the preprint of the Nature paper can be found here.
Some people use Acronym Finder.
^_^
What this article is talking about is the discovery of superfluidity in a fermi gas-ie, flow without resistance. More information can be found about it from physicsweb