Honestly, I’m not smart enough to comment intelligently on this, but I can say “Day-ummmm! Them’s some really smart people!”
Originally shared by Lacerant Plainer
Quantum whirlpools : Trying to understand the superfluid state of helium, have led researchers to finally create quantum whirlpools as observed earlier. Dr. Elena Ostrovskaya from ANU (Australian National Univ.) has said it has been a challenge to control these vortices (circulating currents of polaritons) before. “The vortices have previously only appeared randomly, and always in pairs that swirl in opposite directions,” said Dr. Robert Dall, who led the experimental part of the project. “However, by using a spiral mask to structure our laser, we create a chiral system that prefers one flow direction. Therefore we can create a single, stable vortex at will.” These vortices are an example of quantum fluid behavior in which the polaritons coalesce into a rare state of matter known as a Bose-Einstein condensate.
Polaritons : Polaritons are hybrid particles that have properties of both matter and light. The ability to control polariton flows in this way could aid the development of completely novel technology to link conventional electronics with new laser and fibre-based technologies. Polaritons form in semiconductors when laser light interacts with electrons and holes (positively charged vacancies) so strongly that it is no longer possible to distinguish light from matter.
Bose-Einstein condensates : “The beauty of a Bose-Einstein condensate is that it is similar to a laser but made of matter,” Dr Davis said. “It is a collection of atoms that are perfectly coherent and have the potential to be used in ultra-sensitive measurement devices.” BECs were first predicted in the 1920s by Einstein.
Spiral masks : The team created the spiral beam by putting their laser through a piece of brass with a spiral pattern of holes in it. This was directed into a semiconductor microcavity, a tiny wafer of aluminium gallium arsenide, a material used in LEDs, sandwiched between two reflectors. “By using a spiral mask to structure our laser, we create a chiral system that prefers one flow direction. Therefore we can create a single, stable vortex at will.”
References
Anu.edu: http://www.anu.edu.au/news/all-news/spiral-laser-beam-creates-quantum-whirlpool
Univ of Queensland: http://www.uq.edu.au/news/article/2007/09/jumping-quantum-whirlpool
Science20: http://www.science20.com/news_articles/quantum_whirlpool_stirred_by_spiral_laser_beam-149291
Polariton: http://en.wikipedia.org/wiki/Polariton
Pic courtesy: SLAC (Stanford Univ.)
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