arXiv: <a href="https://arxiv.org/pdf/1606.08795.pdf" rel="nofollow">https://arxiv.org/pdf/1606.08795.pdf</a><p>By the way, this group achieved ground-state cooling of a very similar mechanical oscillator back in 2011.<p>"Sideband cooling of micromechanical motion to the
quantum ground state" <a href="http://www.nature.com/nature/journal/v475/n7356/abs/nature10261.html" rel="nofollow">http://www.nature.com/nature/journal/v475/n7356/abs/nature10...</a> arXiv: <a href="https://arxiv.org/abs/1103.2144" rel="nofollow">https://arxiv.org/abs/1103.2144</a><p>Both oscillators were of roughly the same frequency (10 MHz) and size (~15 nm diameter aluminum disc). In terms of phonon occupation number, things improved from 0.34 to 0.19.<p>They emphasize in this new paper that they were able to get colder by using a squeezed vacuum state of laser light. I'm no expert, but I think the use of this technique is much more important than the improvement in the mechanical state they were able to achieve.
I've often read that absolute zero (0 K) is impossible to obtain, but never really understood whether it's just for practical reasons or if there's actually a theoretical background.<p>As far as I understand, there's no reason why a particle having 0 kinetic energy can't exist. Also, achieving it seems theoretically possible when a particle has kinetic energy equal to one photon, then emits a photon. Obviously it's hard to experimentally produce such a situation, but not theoretically impossible.<p>So, would 0 K theoretically be possible or am I missing something?
For those curious of possible applications:<p><i>Sensors would become more sensitive. You can store information longer. If you were using it in a quantum computer, then you would compute without distortion, and you would actually get the answer you want.</i>
From the article: "squeezed light removes the generally accepted cooling limit". Generally removing a limit in physics is a huge deal. What was this limit based on? Has some fundamental quantum physical property been disproven? Is this a breakthrough more significant than setting a coldness record? Was the generally accepted limit based on what would be "really tough" or something else? Anyone know?
How can something have a fraction of a quantum of energy? I thought energy levels had to be discreet integer multiples of Planck's constant? The more I read about Quantum Mechanics, the less I understand!