A new technique for isolating atoms may one day help physicists manipulate individual atoms with the same ease as they are able to isolate light particles in a laboratory. Physicist Andrew Truscott and his colleagues at the Australian National University, in the city of Canberra, used magnetic fields to trap 10,000 helium atoms cooled to a state of matter known as a Bose-Einstein condensate, in which all atoms behave in unison, like a single larger atom. Then, they used an electric field to increase the number of collisions between the atoms in the condensate, pushing them out of the trap in pairs (Physical Review Letters, September 24, 2014). So if an odd number of helium atoms was initially present in the trap, a single atom would be left in the end, at a temperature of just 890 trillionths of a degree Celsius (°C) above absolute zero (-273°C). Under the laws of quantum mechanics, an atom cooled to such low temperatures behaves more like a wave than a particle, which means that the atoms isolated by the new technique will be perfect for testing quantum phenomena like entanglement, which has already been tested using pairs of light particles.
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