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Quantum Machine Appears to Defy Universe’s Push for Disorder (quantamagazine.org)
84 points by biofox on March 21, 2019 | hide | past | favorite | 15 comments


And almost offtopic, in a scifi story, an advanced civilization found a way to extract energy from these systems billion of years ago (or use them just to store stuff, lot of it). Taking positive energy out of the system creates negative energy which is inflating the universe faster and faster. Most of them don't care because it will take billion of years for matter to be stirred into pieces. Some of them think it's not a good idea and should be controlled somehow but cheap energy is too tempting.



That's a pretty blunt metaphor for fossil fuels.


Did they have Global Schrodingering deniers?


The more they study quantum phenomenon, the crazier the things they find. I suspect quantum computers will take longer than expected to make practical, but researchers will find interesting phenomenon along the journey that may eventually lead to other practical tools.


Purely intuitively, the 'scarrig' seems to limit the state space for this 51-qubit quantum system.

So it is not clear why the authors believe this development will lead to better quantum computers.


The state space is constrained because the Rydberg blockade forces it to grow in a certain manner like the Fibonacci sequence. Lukin and Ho come up with a toy model that shows some features but it’s not clear it captures all the physics. The authors make this statement because people want passive (not optimal control) ways of preserving quantum information that aren’t (quantum) integrable. (I can go into detail on the definitions here if you want.)

NB: my department chair was Rick Heller’s grad student and we’ve been discussing these preprints here just like everyone else


Maybe an example or related to time crystals?

https://en.wikipedia.org/wiki/Time_crystal


"Scar (physics)": https://en.wikipedia.org/wiki/Scar_(physics)

> Scars are unexpected in the sense that stationary classical distributions at the same energy are completely uniform in space with no special concentrations along periodic orbits, and quantum chaos theory of energy spectra gave no hint of their existence


Time crystals generally require active driving of some sort. They have a periodic behavior the opposite of parametric oscillation. A key feature of most time crystals is their long ‘prethermalizing’ behavior which is to say that it behaves like it isn’t thermalized for some very long but finite time. Whether these scars decay similarly especially within this constrained SU(2) space Lukin has cooked up is still out.


Here’s a nice paper on prethermaliztion - https://arxiv.org/abs/1812.04776


Is the Second Law dead?


There's a saying in physics that if your theory predicts the demise of General Relativity or Quantum Mechanics, you might have just earned a Nobel Prize, but if your theory violates the Second Law of Thermodynamics, there's no hope: you better go check your work again.


I love how they are giving cows grazing grass as an analogy leading to the possible explanation of the quantum effects. Of course, as cows are lazy to climb hills, atoms are also lazy to climb the invisible hills so they roll back to the valley). It's proof that a farmer heard the "whoever solves this gets a nobel prize", and wanted to give it a go.

I 'll give it a go too. IT'S A RACING CONDITION!!!! See. In the latest patch, we switched universe rendering from QT to Electron, because we read a very compelling argument on twitter. As you know, certain CSS properties cause reflows, repaint, relayouts. Here, outside of time, WASM still didn't get the needed adoption, so in order to optimize universe rendering, we split it into different threads. However, these threads do not have shared memory, so what happens is you change state in thread A. In order to have you see a loading gif, we make the change locally to your system but it is not propagated everywhere yet, then the render loop runs again, and it overwrites the local change you made. You need to hit the particles with an attribute that will trigger a recalculate style call, not just a repaint, because repaint is overwriten and does not actually modify the element's width and height.

I will stop being throwaway when you need an address for the mr Nobel please! :)


I'd like to stand at the last paragraph of the article above stating “There is some beautiful structure that somehow coexists with a totally random environment,” Papić said. “What kind of physics allows this to happen? This is a kind of deep and profound question that runs through many areas of physics, and I think this is another incarnation.”

This comes as a blow in the face for those who believe that the universe is the result of randomness or that intelligent design is a fairy tale.

My response to Mr Papic is that this is the kind of physics our Creator has built! The kind of physics causing another familiar entity, the DNA, to refuse to submit to entropy as well. It is another proof of the existence of God and He's greatest creation, the Soul!




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