Slashdot Mirror
Cambridge Scientists Create Huge Quantum Particles
judgecorp writes "Researchers at Cambridge University have produced a quantum fluid thousands of times larger than previously, leading to the possibility of polaritons produced at lower power and at a broader temperature range. This could lead to quantum circuits, as well as applications such as more sensitive gyroscopes."
The paper was published in Nature Physics on January 8th, but a pre-press version is available through arXiv.
Quantum linguistics?
or are they past?
Meghan McCain is writing for Slashdot now?
Stop adjectivizing quantum verbs, they don't like it.
ID: the nose did not occur naturally, how would we wear glasses otherwise? (apologies to Voltaire)
Why couldn't they publish a dam video instead of just one small picture that looks like something out of photoshoped vector wallpapers. Teasing a-holes.
-- except in matter,
and if it is dangling participle, it will be smaller
Sounds like bite-sized Klondike bar bits...they should seriously steal that name and use it for ice cream goodness...
When I read the title, this scenario immediately popped into my head:
Physicist A: "We need to make something cool out of them... like one of those tiny violins or the art on a microchip..."
Physicist B: "Let's make boobs! Every sculptor makes boobs eventually! Quantum boobs!"
Physicist A: "OK, but they gotta be HUGE! Then we can use normal particles for the nipples!"
I've been hanging around lonely geeks too long.
US Democracy:The best person for the job (among These pre-selected choices...)
Great! My lights have been needing a bottle of blinker fluid for the longest time!
Does anybody here understand what these scientists have supposedly achieved?
This is in my area of research, and I read and understood the abstract. It does not seem like something that should be posted on Slashdot.
In this case, quantum fluid means a fluid that is cold enough, dense enough, and made of low enough mass particles that it has some quantum mechanical properties (interference is an example in the abstract).
Making a bigger quantum fluid is not really a challenge - you just need a bigger refrigerator and a bigger tank of helium. In this case, they made a bigger quantum fluid of a very specialized type.
But isn't the whole point to quantum science that observation collapses a state into one thing or the other?
No. That is just one small part of quantum mechanics.
Simon's Rock College
I don't understand what's new about polaritons in semiconductor nanostructures. You only need a multi quantum well structure and pump it at the right angle with a laser.
Um... TFA says "larger than usual". Not "larger than before".
I think the record still belongs to Bose condensates that have been created in the lab, essentially amounting to huge single quantum "particles".
I compliment you on your answer. Until I read your post, it appeared that they were working with some form of bolonium laced with unobtainium to make their claims.
Seeing your answer makes me thing some people might also find this helpful:
BEC - What is it and where did the idea come from?
or this..
Bose–Einstein condensation
much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
Told!
The expression "quantum fluid" can be misleading.
What they did here is make a system of coherent "polaritons" just as laser light is a bunch of coherent photons/light waves. As mentioned in the article abstract, a polariton is some combination of a photon (light particle) and an exciton. In turn, an exciton is a bound state of an electron and a hole from the semiconductor. (A hole is the 'vacant' positive charge created when an electron is removed, and may for all practical purposes be regarded as an anti-electron within the semiconductor.) If I understand correctly, the novelty in this work is not making the polariton condensate but the visualization of it. In that sense, the summary if way off.
This is surely not easy to grasp for the layman. What does this imply? As parent mentioned, making coherent quantum states or matter is a standard affair by now, and research focuses on extending our capabilities on all levels. It is necessary for our understanding of the fundamentals of quantum mechanics and how many particles conspire to make laboratory but also everyday matter. The practical possibilities for making devices out of "quantum fluids" is severely limited, since you almost always need extremely low temperatures to produce them. Only superconductors come close.
The SEP field.
This begs the question as to who generates more exitons: Sara Underwood or Candace Bailey?
Views expressed do not necessarily reflect those of the author.
If i understand it correctly, they just made bosson condensate from from polariton quasiparticles.
Bosson condensate is nothing new. Bossons are integer spin particles which means they can occupy the same energy level or quantum state with other bossons of the same type (on other hand, fermions - particles with half integer spin - never occupy same quantum state with other fermions of the same type, that's why electrons are placed in energetic layers around atom nuclei).
Lot of bossons in basic energy state basicaly behave as single particle (they all have same quantum state).
What's new in this experiment is that boson condensate from polariton quasiparticles can have macroscopic dimensions and can exist in room temperatures and it behaves like superfluid!
One simple obvious thing I haven't figured out, is if super-cooled Helium qualifies as a Bose-Einstein condensate, and if not why not? Everything I see on this refers to BEC's being created in 1995, but I equally see the properties of supercooled helium as being due to Bose-Einstein Statistics, even to a point of noting that Helium IV creates a superfluid faster than (at higher temperature) because Helium IV is naturally a boson, while Helium III is only a boson in pairs.
Do superfluids qualify as a condensate, could they qualify if they were cooled further, and what are the actual differences between a Helium IV superfluid and a condensate?
Small words only please boson-breathe - {grin}
Pug
An Invisible Entity of Vast Power whose existence must be taken on faith alone: Liberal Media
I know the menagerie of particles and things-we-like-to-model-as-if-they-were-particles becomes huge.
Even so, after starting my morning with an article about quantum "polaritons", I will have this running through my head all day...
Lyrics here if you don't want your friends to know you listen to goth trek filk.
"Reality is that which, when you stop believing in it, doesn't go away." - Philip K. Dick
One simple obvious thing I haven't figured out, is if super-cooled Helium qualifies as a Bose-Einstein condensate, and if not why not? Everything I see on this refers to BEC's being created in 1995, but I equally see the properties of supercooled helium as being due to Bose-Einstein Statistics, even to a point of noting that Helium IV creates a superfluid faster than (at higher temperature) because Helium IV is naturally a boson, while Helium III is only a boson in pairs.
Do superfluids qualify as a condensate, could they qualify if they were cooled further, and what are the actual differences between a Helium IV superfluid and a condensate?
(Yes I work in BEC)
Helium 4 becomes superfluid at low temperatures because there is Bose-Einstein condensation present in the Helium, but it's only a small fraction of the total sample (at very low temperatures the condensate fraction is ~ 10%, while the superfluid fraction is in ~ 100%). The actual situation in this system is massively complicated by the fact that Helium is a liquid in this regime.
Einstein's prediction of condensation was for an ideal gas (i.e., no interactions between the atoms). The novelty here is that the transition to a different phase of matter is therefore driven by the quantum statistics, rather than interactions between the atoms (as in every other phase transition).
The next-most-simple scenario is a near-ideal gas, i.e., a bunch of atoms which scatter off one another (in one-on-one collisions only), and which don't scatter very hard. This system will also undergo condensation, though of course some pedants will argue that it isn't the Bose-Einstein transition anymore because interactions are present. It's very closely related though.
This near-ideal-gas system provided (in ~ 1950s ) a theoretical basis for qualitatively understanding superfluid Helium, despite the fact that it's a terrible approximation, as liquid Helium is just that: Liquid, and so the atoms are interacting with one another like crazy. The condensates realized in the late nineties are formed in gaseous samples, where the near-ideal-gas type of model can be quantitatively accurate, and virtually 100% pure condensates can be formed in this way. One upshot of this is that you can observe a lot of the phenomenology that is associated with all BEC in principle, but which in practice would be impossible to observe in a system like liquid Helium.
they follow you home.
As long as they don't hog the sofa!
If Google really cared they would fix Android Chrome to reflow text, instead of discriminating
And the beauty of this fluid is that if you spill it it ceases to exist!
No mess, no fuss and no cleaning up.
A closed mouth gathers no foot.
Next, we get quantum conjugates... Would they be called quanjugates? :-)
If it helps Polaritons don't belong in the standard model megagerie. They are quasi-particles. Collective states can (often) be modelled as a system with the number of quasi-particles representing the excitation of the system, if these quasi-particles have well defined properties, act at point, commute with other useful observable then its a useful description of reality, but its still just electrons and nucleii as usual. Quasi-particles are very useful at reducing complex system to simple ones in condensed matter.
They either created quantum particles or they didn't. I'm going to check, and I'm sure they didn't. Sure enough.