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This is so kewl. Here's why:
For those who forgot or don't know what quantum entanglement is:
But ...
But not this time. They managed to achieve this in macroscopic objects at room temperature! They used two squares of synthetically produced diamond, each 3mm across and a laser pulse, bisected by a beam splitter, passing through the diamonds and a photon detector. A phonon which was generated in the process helped them to realize that entanglement did actually happen. Even though the process didn't last long (only few picoseconds) they ran experiment over and over again to gather statistically significant results which made them conclude with confidence that entanglement had indeed been achieved.
To verify the process they did this:
Oxford and NUS physicist Vlatko Vedral, who was not involved in the new research, says:
So here we have it, quantum laws in everyday life. I found this article @ Scientific American
http://www.scientificamerican.com/article.cfm?id=room-temperature-entanglement
Other interesting articles from SA:
http://www.scientificamerican.com/article.cfm?id=high-noon-entanglement
http://www.scientificamerican.com/article.cfm?id=living-in-a-quantum-world
A group of researchers report in the December 2 issue of Science that they managed to entangle the quantum states of two diamonds separated by 15cm.
For those who forgot or don't know what quantum entanglement is:
Quantum entanglement is a phenomenon by which two or more objects share an unseen link bridging the space between them—a hypothetical pair of entangled dice, for instance, would always land on matching numbers, even if they were rolled in different places simultaneously.
But ...
But that link is fragile, and it can be disrupted by any number of outside influences. For that reason entanglement experiments on physical systems usually take place in highly controlled laboratory setups—entangling, say, a pair of isolated atoms cooled to nearly absolute zero.
But not this time. They managed to achieve this in macroscopic objects at room temperature! They used two squares of synthetically produced diamond, each 3mm across and a laser pulse, bisected by a beam splitter, passing through the diamonds and a photon detector. A phonon which was generated in the process helped them to realize that entanglement did actually happen. Even though the process didn't last long (only few picoseconds) they ran experiment over and over again to gather statistically significant results which made them conclude with confidence that entanglement had indeed been achieved.
To entangle relatively large objects, researchers harnessed a collective property of diamonds: the vibrational state of their crystal lattices. By targeting a diamond with an optical pulse, the researchers can induce a vibration in the diamond, creating an excitation called a phonon—a quantum of vibrational energy. Researchers can tell when a diamond contains a phonon by checking the light of the pulse as it exits. Because the pulse has deposited a tiny bit of its energy in the crystal, one of the outbound photons is of lower energy, and hence longer wavelength, than the photons of the incoming pulse.
To verify the process they did this:
To verify the presence of entanglement, the researchers carried out a test to check that the diamonds were not acting independently. In the absence of entanglement, after all, half the laser pulses could set the left-hand diamond vibrating and the other half could act on the right-hand diamond, with no quantum correlation between the two objects. If that were the case, then the phonon would be fully confined to one diamond.
If, on the other hand, the phonon were indeed shared by the two entangled diamonds, then any detectable effect of the phonon could bear the imprint of both objects. So the researchers fired a second optical pulse into the diamonds, with the intent of de-exciting the vibration and producing a signal photon that indicates that the phonon has been removed from the system. The phonon's vibrational energy gives the optical pulse a boost, producing a photon with higher energy, or shorter wavelength, than the incoming photons and eliminating the phonon in the process.
Oxford and NUS physicist Vlatko Vedral, who was not involved in the new research, says:
It "beautifully illustrates" the point of Austrian physicist Erwin Schrödinger's famous thought experiment in which a hypothetical cat is simultaneously alive and dead. It can't be that entanglement exists at the micro level (say of photons) but not at the macro level (say of diamonds), because those worlds interact. Schrödinger used atoms instead of photons and cats instead of diamonds, but the point is the same.
So here we have it, quantum laws in everyday life. I found this article @ Scientific American
http://www.scientificamerican.com/article.cfm?id=room-temperature-entanglement
Other interesting articles from SA:
http://www.scientificamerican.com/article.cfm?id=high-noon-entanglement
http://www.scientificamerican.com/article.cfm?id=living-in-a-quantum-world
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