A Supersolid Made Using Photons
photonicsonline.com
photonicsonline.com
I guess "solid" has a technical definition that allows for this sort of interesting interpretation.
So you read it correctly: scientists made a fancy electric field with a laser.
"At the mean field level, supersolidity can be interpreted as two-mode condensation; after condensation in the first, a second mode become senergetically available by tuning of interactions or an external electromagnetic field and can then be dynamically populated."
This is just messing with us right? Star trek level technobabble?
Just kidding, seems an exciting result, even if it flies way over my head.
- Supersolid: it's a state of matter when a system is both organised like a solid but presents superfluid-like flow without viscosity.
- Driven-dissipative: it's a qualifier for systems which are dissipative (excitations of the systems dissipate energy as heat) and driven by external fields (in this case strong electromagnetic fields are keeping the supersolid in shape). In physics, "driven" usually refers to an external influx of energy or force kept on the system.
- non-equilibrium system is what we call systems where the physics cannot be fully described by a statistical analysis of the whole over long times. These systems have transitory behaviours which are often complex before they return to equilibrium (unless they are driven away from it).
Exciton-polariton: excitons and polaritons are what we call quasiparticles. They're not particles in the sense of an electron or photon, but instead they are excitations of the collective system which look like particles. Kind of like how waves on the ocean aren't one water molecule, but a bunch of them. An exciton has no charge (it's essentially an electron and a missing electron stuck together). When an exciton couples to electromagnetic waves (photons), it can make a special type of polariton (another quasiparticle) which we call an exciton-polariton.
- Photonic = made of photons
This is hard for me to grasp. For example, if it bumps hard into a hard solid surface, does it shear like, say, bent metal? Or is it itself 'hard' / rigid - if that is a reasonable descriptor for something at such small scales - itself, and - despite being able to flow, with no friction, smoothly - still remain 'locked in shape' at a structural level? My real question I guess is how does a collision work here?
https://en.wikipedia.org/wiki/Electron_hole
but it's more like a way of describing a system.
Which also means that nobody is making a solid object from photons, it's all "behaves like a solid would if you look at our system a certain way". Right?
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Also - I don't see how the phrases "behaves like a solid" and "presents flow" can agree. Isn't the whole point of a solid that it _doesn't_ flow?
First, just like a superfluid, a supersolid can have a portion that flows and one that doesn't (the normal fraction).
The second part is that, as you rightfully mentioned, holes are just vacancies in the structure. Here the vacancies in the crystalline structure they made are able to flow along the solid. But as they flow, the structure retains its shape. And at low enough temperature, these excitations condense into a macroscopic quantum state which makes them a superfluid.
So in a nutshell, you have an organised structure like a solide, but a portion of that structure flows without breaking the overall structure.
Ah yes, classic move. Clearly, by aligning the polaritons within the photonic crystal’s inverse reactive current, they’ve essentially reinvented the Retro Encabulator. It’s good to see someone finally tackling the long-standing issue of modial photon-density modulation. But I have to wonder—did they adequately compensate for sinusoidal repleneration in the supersolid wavefunction, or are we looking at another premature quantum flux leakage scenario? Call me when they’ve integrated ambifacient lunar waneshafts and a turbo-encabulated photon lattice. Until then, color me photonically unimpressed.
(dingle-arm, he actually said dingle-arm!)
https://www.youtube.com/watch?v=5nKk_-Lvhzo
(and he said transmogrified!)
An odd solid that can flow like a fluid has been created from light for the first time. Studying it will help researchers better understand exotic quantum states of matter. “We actually made light into a solid." ... light-based supersolids may be easier to manipulate than those previously created with atoms, which could make his team’s experiment a first step towards understanding a slew of novel and surprising types of matter.
Italy: CNR National Institute of Optics, University of Pavia
USA: Princeton University, Lawrence Berkeley National Laboratory
Austria: University of Innsbruck
> Under these extreme conditions, matter starts behaving very differently from what we are used to.. More than half a century ago, physicists predicted the existence of a "supersolid" state. It is matter that has the properties of both a solid and a superfluid, in which a fraction of the atoms flow friction-free through the lattice – a regular arrangement of points or objects – of a rigid crystal structure.. A series of tiny whirlpools, or quantised vortices, begin to appear.. These are like small holes in the fluid, each rotating at a specific speed.. they arrange themselves in beautiful, regular patterns across the surface of the superfluid, almost like the holes in a piece of Gruyere cheese, but perfectly organized.