NielsBohrInstitute
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Researchers use lasers to supercool semiconductor membranes, blow your mind
Ah, lasers. Those wonderful, super intense beams of light that we've seen used in headlights, projectors, and naturally, death rays. Like us, researchers at the Niels Bohr Institute at the University of Copenhagen figure there's nothing lasers can't do, and have figured out a way to use them to cool a bit of semiconducting material. This bit of black magic works using a membrane made of gallium arsenide and is based upon principles of quantum physics and optomechanics (the interaction between light and mechanical motion).Turns out, when a one millimeter square membrane of gallium arsenide is placed parallel to a mirror in a vacuum chamber and bombarded with a laser beam, an optical resonator is created between them that oscillates the membrane. As the distance between the gallium arsenide and the mirror changes, so do the membrane's oscillations. And, at a certain frequency, the membrane is cooled to minus 269 degrees Celsius -- despite the fact that the membrane itself is being heated by the laser. So, lasers can both heat things up and cool them down simultaneously, and if that confuses you as much as it does us, feel free to dig into the science behind this paradoxical bit of research at the source below. In other news, left is right, up is down, and Eli Manning is a beloved folk hero to all Bostonians.
Michael Gorman01.24.2012
Galaxy cluster research supports Einstein's Theory of Relativity on a cosmic level
In one small win for Einstein, one giant win for mankind, scientists at the Niels Bohr Institute have proved his General Theory of Relativity on a cosmic scale through their research of large galaxy clusters. Accordingly, the clusters -- which are the largest known gravity-bound objects -- have such a strong pull that they should cause light to "redshift," or proportionally increase in wavelength, shifting towards the red end of the visible spectrum. To test it, researchers measured beams from 8,000 clusters, revealing that they do indeed cause a change in light's wavelength, supporting Einstein's theory to a T. One good turn deserves another, right Albert? Armchair cosmologists can hop on over to the source link to learn more.
Lydia Leavitt09.30.2011
Quantum entanglement could mean completely secure data transfer
By tapping into Albert Einstein's idea of "spooky action at a distance," researchers at the University of Copenhagen's Niels Bohr Institute have discovered what might be the key to completely secure data transfer -- keeping particles "entangled" for up to an hour. Until now, the link between two entangled systems could only be maintained for a fraction of a second. This development could enable a direct link between two systems of communication -- you do something to one and the other will "know." Although limited to the lab right now, scientists are working on practical applications for networking and the internets. Hey, SSH maybe it's time you started watching your back. Check out the full PR after the break. [Thanks Nan]
Lydia Leavitt08.21.2011
Danish scientists achieve advanced quantum teleportation
As you can imagine, here at Engadget, we love it when science fiction becomes more science and less fiction. With that in mind, we're pleased to pass along the news that Danish scientists at Copenhagen University have made a breakthrough in the wacky world of quantum teleportation by transporting quantum information over a distance of half a meter (1.6 feet). In order to achieve this, Dr. Eugene Polzik and his team shined a strong laser beam into a cloud of room-temperature cesium atoms that shared the same directional spin. As Scientific American reports: "The laser became entangled with the collective spin of the cloud, meaning that the quantum states of laser and gas shared the same amplitude but had opposite phases. The goal was to transfer, or teleport, the quantum state of a second light beam onto the cloud." (It should be noted that this process is more akin to duplication than actual teleportation, i.e. using this method on a human being would result in the formation of a doppelganger and not a magical Star Trek-like movement of matter). To achieve this goal, Polzik and other scientists added a second weaker laser pulse and split the two beams into separate branches in order to measure the difference between the quantum phases; through that measurement the scientists were then able to transfer the information of the spin state of the weak laser to the combination of the cesium atoms and the strong laser, without disturbing the quantum entanglement between the laser and the cesium. Umm, so the short of it is: one small step for a cesium atom, but one giant leap for quantum computing research and the advancement of teleportation theory.[Thanks, Josh H. and Eric M.]Read - ReutersRead - Scientific American
Cyrus Farivar10.05.2006