Scientists Discover a 'Tuneable' Novel Quantum State of Matter (phys.org) 82
An anonymous reader quotes a report from Phys.Org: An international team of researchers led by Princeton physicist Zahid Hasan has discovered a quantum state of matter that can be "tuned" at will -- and it's 10 times more tuneable than existing theories can explain. This level of manipulability opens enormous possibilities for next-generation nanotechnologies and quantum computing. Hasan and his colleagues, whose research appears in the current issue of Nature, are calling their discovery a "novel" quantum state of matter because it is not explained by existing theories of material properties. The classical phases of matter -- solids, liquids and gases -- arise from interactions between atoms or molecules. In a quantum phase of matter, the interactions take place between electrons, and are much more complex.
[Hasan] and his colleagues arranged atoms on the surface of crystals in many different patterns and watched what happened. They used various materials prepared by collaborating groups in China, Taiwan and Princeton. One particular arrangement, a six-fold honeycomb shape called a "kagome lattice" for its resemblance to a Japanese basket-weaving pattern, led to something startling -- but only when examined under a spectromicroscope in the presence of a strong magnetic field [...]. All the known theories of physics predicted that the electrons would adhere to the six-fold underlying pattern, but instead, the electrons hovering above their atoms decided to march to their own drummer -- in a straight line, with two-fold symmetry. The decoupling between the electrons and the arrangement of atoms was surprising enough, but then the researchers applied a magnetic field and discovered that they could turn that one line in any direction they chose. Without moving the crystal lattice, [one] could rotate the line of electrons just by controlling the magnetic field around them.
[Hasan] and his colleagues arranged atoms on the surface of crystals in many different patterns and watched what happened. They used various materials prepared by collaborating groups in China, Taiwan and Princeton. One particular arrangement, a six-fold honeycomb shape called a "kagome lattice" for its resemblance to a Japanese basket-weaving pattern, led to something startling -- but only when examined under a spectromicroscope in the presence of a strong magnetic field [...]. All the known theories of physics predicted that the electrons would adhere to the six-fold underlying pattern, but instead, the electrons hovering above their atoms decided to march to their own drummer -- in a straight line, with two-fold symmetry. The decoupling between the electrons and the arrangement of atoms was surprising enough, but then the researchers applied a magnetic field and discovered that they could turn that one line in any direction they chose. Without moving the crystal lattice, [one] could rotate the line of electrons just by controlling the magnetic field around them.
"That's funny" (Score:5, Interesting)
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Re:"That's funny" (Score:5, Funny)
The most exciting phrase to hear in science, ... is not “Eureka!” (I found it!) but “That’s funny ” ...
Interestingly, they tie as least exciting phrase to hear in bed.
Re:"That's funny" (Score:5, Insightful)
I'm still waiting for the headline "Sports team discovers new...", or "Religion discovers new..."
Re:"That's funny" (Score:4, Funny)
I'm still waiting for the headline "Sports team discovers new...", or "Religion discovers new..."
"Religion discovers new way to impede science." There ya go.
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We don't need religion to manipulate the masses. I don't buy into the idea of a better world without religion BS. People are just going to hang onto some some other ideal to base their excuse to being cruel to other people. ....
Look at just some of the emotions we get from the stupidest things.
Android vs iOS
Linux vs Windows
Emacs vs VI
PC vs Mac
CICS vs RISC
Eating Pizza with a fork
White after labor day
The color of Clam Chowder
how to pronounce Chowder/Chowd'a
Pineapple on a pizza.
Ford vs Chevy
Re:"That's funny" (Score:5, Informative)
"Religion discovers new..."
Fun fact: Historically, the Catholic Church has been a major sponsor of astronomy. Catholic Church backed and help make plenty of scientific discoveries. [wikipedia.org] They have had poor reactions to some discoveries but contributed a lot to making them.
Sounds more classical than quantum. (Score:5, Interesting)
All the known theories of physics predicted that the electrons would adhere to the six-fold underlying pattern, but instead, the electrons hovering above their atoms decided to march to their own drummer -- in a straight line, with two-fold symmetry. The decoupling between the electrons and the arrangement of atoms was surprising enough, but then the researchers applied a magnetic field and discovered that they could turn that one line in any direction they chose. Without moving the crystal lattice, [one] could rotate the line of electrons just by controlling the magnetic field around them.
Sounds classical to me:
- The layout of the substrate produced a planar potential well with no, or very little, difference of energy for electrons being in one position vs. another.
- Provided the average density of the electrons was right, they behaved like a gas of individual particles in a thin container, or marbles on a flat surface.
- The electrons repelled each other, so they tended to spread out evenly. (Spread out too far, though, and they leave some positive-charged substrate behind. So they don't just fly apart and go away.)
- But electrons also have spin, which means they are little magnets. So, with their mutual repulsion largely defeated by forces holding them at a given average spacing, they tend to line up north-pole-to-south-pole in strings (but don't all pile up because coming more than a little closer together under the slight magnetic attraction is balanced by higher repulsion.) The strings are a bit more dense than the average gas, so most of the electrons join one and reduce their total energy.
- So now you have these long magnetic strings, with no preferred orientation driven by irregularities in the substrate. Bring a magnet nearby and they'll line up with its field while spacing out by mutual magnetic AND electrostatic repulsion, much like iron filing lines.
Re:Sounds more classical than quantum. (Score:5, Interesting)
Also: Sounds like the electrons were far enough apart and unassociated enough with the nearby nuclei that the Pauli-exclusion effects weren't constraining them into particular states - or the states were close enough together to act more like a continuum.
Re:Sounds more classical than quantum. (Score:4, Funny)
Re: Sounds more classical than quantum. (Score:2, Informative)
There are five. You forgot Bose-Einstein condensate.
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Bose-Einstein condensate is not a classical state of matter, it's a modern state.
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You could have just said it was a compass.
Just kidding; great post. Even so, I'm curious if you read the nature article. I'm guessing that the blurbs are misleading. I looked at the start, but it's pay walled and probably beyond my level of physics. I wondered if they moved it around and saw the compass effect?
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You could have just said it was a compass.
Yep.
Or at least a bunch of charged-so-they-repell-each-other "compass needles" on a flat slippery surface.
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7 comments (Score:5, Funny)
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Bogus nonsense? Tell us that the next time you need an infintesimally small magnetometer for some project.
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The next time you need a tiny magnetometer that only works in a unique and temperamental two-story agglomeration of exotic technology, anyway.
What are the applications? (Score:2)
This sounds cool but I feel like every time there is a big announcement about something amazing involving Quantum Physics, the first thing everyone mentions is how it'll be useful in nanotechnology and quantum computing. Unfortunately, no one ever really explains how its useful and what the actual application in those fields are, so I'm left wondering if any of this is really that useful or just simply that the reporters have 0 clue and just toss that in to make it seem important.
Re:What are the applications? (Score:5, Interesting)
And that is the correct reaction. Bose-Einstein condensate [wikipedia.org] is the worst offender in overhyping their significance—name a single useful thing that came out this Nobel-prize-winning discovery!
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Nope! Look for BEC here [wikipedia.org], I dare you.
That's what they claimed BEC could do; no one has done it. The thing is, lifetime of a BEC is so short (last I heard, on the order of a few seconds), that itself puts significant constraints on precision measurements you can do.
This is what it comes down to—there have been so few truly new discoveries in physics, that many physicists have become hype artists. If they tell you they discovered something new, bet (on even-money odds) that they didn't. If you can find s
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It's worse than that - most BECs have a lifetime of fractions of a second. One of the limiting factors on the lifetime of a BEC is, oddly enough, gravity: the clump of particles simply falls out of the trap. A recent delivery to the International Space Station will allow for the creation of BECs with longer lifetimes: 5-10 seconds accord [nasa.gov]
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That sentence contained so many internal contradictions that it's not even wrong [columbia.edu]. Congratulations! You have created the perfect troll post to give an actual physicist an aneurysm!
Re: What are the applications? (Score:2)
Though I have no idea if the current research on BEC is related to this in any way.
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Fortunately, I have successfully fought one aneurysm, and more aneurysms are not going to hurt me.
Hey, I know as much medicine as you know physics. "Superfluid is a Bose-Einstein Condensate" is the kind of nonsense that people in the racist South would say.
Re: What are the applications? (Score:1)
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I say you don't know how to read.
Re: What are the applications? (Score:2)
This is other physicists discussing the same question, do it is obviously not obvious. And at least two answers state that BEC is a prerequisite for superfluidity.
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And you are just cherry-picking to, I don't know what you are doing, because you are not saving any face with your continued insistence in ignorary.
Yes, I've been insulting to you, and that's because you are so willfully ignorant. If you know nothing about low-temperature physics and ultra-cold gases, admit that and say that you don't know, rather than trying to bullshit your way around. I am not going to bother to try to teach to the unteachable.
Come back when you have learned some humility.
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I am not a specialist in low-temperature physics. The professor who stated that connection back when I studied worked on low-temperature experiments though.
I don't know why you don't see that connection. In what I linked to is one paragraph which is not clear to me, I guess it does when you work in the fi
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You don't need to be a specialist to understand that superfluid is not BEC. They are "related" in the sense that they both involve reaching a macroscopic quantum state by approaching the groundstate of a system involving many particles (you can put superconductor in the same category for that; the Internet forum you linked mentioned Cooper pairs).
But to use that relationship to say that superfluid is BEC is at best oversimplifying (a very dangerous thing to do when you are not a specialist in the field, hen
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Actually I just remember reading the paragraph on superliquid Helium in that physics book. It wasn't more than a pragraph and must have been new to the author. So it might have been written up to 50 years ago. Well, it's often a problem on such boards
Re:What are the applications? (Score:5, Insightful)
Yeah, just think back when lasers were invented, there was absolutely no use for it then. What a waste of time that was.
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Are you sure? First invention of maser: 1953 (one of the fruits of the postwar research). Invention of hydrogen maser (part of atomic clock standard—the actual standard, not some pie-in-the-sky dream of a fevered tenure-seeking researcher): 1962. Only 9 years to a discovery that had lasting practical applications both in science and engineering.
First BEC was produced in 1995. More than 20 years later, still no use for it, either in science or engineering. People are still trying to do stuff with it, b
Re: What are the applications? (Score:5, Insightful)
So 20 years is your limit? What about 30 years? 100 years? Point is that the path from scientific discovery to technical application is sometimes a very long and winding road, other times a straight path (eg transistor).
The BEC was a big deal, even if we don't have an application yet. We discovered a new state of matter with unique properties. That should be what the physics field is excited about, full stop. That it hasn't resulted in an application yet on an arbitrary time horizon is irrelevant to it's scientific value. Should we stop studying dark matter, or neutrinos, because we don't have an application in mind (yet)?
This, by the way, is ignoring the side benefits of the pursuit of BEC. Cornell and others pushed the limits of lasers in order the get the laser cooling required to create the BEC. Their research has also led to advancements in atom and ion trap technologies.
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Yeah, that's the old chestnut: let's send men to the moon, so that we can invent better pens.
I am not saying "don't fund BECs" (I have many former colleagues who'd be mad at me if that's what I was saying). I am saying don't just take scientists at their word when they are trying to hype their own work. If you think used-car salesmen are terrible people when they are trying to sell, physicists are even worse people when they are trying to present their tired, old work as "novel".
While I wouldn't exactly pro
Re: What are the applications? (Score:2)
That's a deceptive oversimplification of the technological side-benefits of scientific research. You don't send people to the moon because you want to make better pens. You do it for a lot of scientific and non scientific reasons (in that case mostly political), and the advancements made along the way can and sometimes do benefit society. The space program is rife with such benefits, much more important than pens. So are particle collider programs.
I get that you don't want to trust scientists when they are
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Indeed. Agreed on the considerations in funding priority. Fundamental science research is basically a speculative venture—you don't want to do none of it (because that means you limit yourself to a box of knowns), but you don't want your next meal coming from it (... which is I guess why the government has to fund a big portion of it).
Re:What are the applications? (Score:4, Interesting)
I'm just an interested layperson, but the applications in nanotechnology seem pretty straightforward to me. Nanotech is basically all about building machines on a scale where a couple individual particles can be a whole part of the machine. So every weird thing you can figure out how to make particles do, on the individual level, at that scale -- as opposed to things to make huge aggregates of particles do -- is something you can use as a part of a nanomachine.
In this case, it sounds like they've figured out a way to build a kind of rod of electrons stuck to a crystal surface, that can be made to rotate based on the application of a magnetic field. That sounds like it could be as useful as, I dunno, a wooden disc that can be made to rotate around an axle is on a macroscopic scale. It sounds dumb and useless when you phrase it like that, but that's a rudimentary wheel, and there's a zillion uses in more complex machines that wheels can be put to. Who knows what exact uses a controllably spinning rod of electrons on the surface of a crystal could be in nanotechnology, but it seems like the kind of thing that could have many and varied.
current theory (Score:2)
If have an experiment that current theory can't explain, you most likely have made a mistake somewhere.
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The classical states (Score:5, Insightful)
Are used as a matter of simplification. There is no clean boundary, only a continuum where the classical states (solid, liquid, gas, plasma) are specific islands.
Quantum doesn't mean magical, it just means something with discrete states rather than continuous states. QM is a quantum theory that mostly applies to the very small but can scale up to objects of a few millimetres under some conditions. Actually, some aspects - such as the Schrodinger Equation - applies to planetary rings, asteroid belts and accretion disks.
The first question is whether it's useful to talk of states of matter. If it is, is it useful to use traditional ones or should we decompose phenomena into the raw properties and then compose a new set of states that reduces the need for weird overlaps and talk of mysteries beyond the ken of man?
The second question (or third, if you go with the option above) is whether something that is apparently orthogonal to the original list is a state in the original sense? The original sense is a linear continuum, not a set of sets. This new thing is apparently not on that line. If matter's state is multidimensional, our naming should reflect that.
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Quantum doesn't mean magical,
Ironically, that may be the most commonly used meaning of the term. For example, we know that the earth is flat but quantum mechanics make it look round. I saw that in a video.