Scientists Using Lasers To Cool Molecules 169
An anonymous reader writes "Ever since audiences heard Goldfinger utter the famous line, 'No, Mr. Bond; I expect you to die,' as a laser beam inched its way toward James Bond and threatened to cut him in half, lasers have been thought of as white-hot beams of intensely focused energy capable of burning through anything in their path. Now a team of Yale physicists has used lasers for a completely different purpose, employing them to cool molecules down to temperatures near absolute zero, about -460 degrees Fahrenheit. Their new method for laser cooling, described in the online edition of the journal Nature, is a significant step toward the ultimate goal of using individual molecules as information bits in quantum computing."
Been done before (Score:1, Interesting)
Isn't Heat Related To Both Velocity and Vibration? (Score:2, Interesting)
If memory serves, the heat of a group of atoms is based both on their kinetic energy and vibrational energy. In gasses and, to a lesser extent, liquids, the average velocities of atoms is one factor determining factor of how much heat is in the gas or liquid, but so is the vibrational energy of the atom (otherwise solids wouldn't be capable of getting hot, which they clearly can).
So while these scientists have demonstrated being able to reduce the kinetic energy of an atom to zero, the article says nothing about being able to do so for its vibrational energy. It seems very possible that hitting an atom with lasers may be able to reduce its kinetic energy but may, depending on the frequency of light used, actually increase its vibrational energy.
So, this approach may work fine for gasses, in which certain atoms can be made motionless and, as long as you keep other atoms from interacting with them, they never pass on their vibrational energy, and thus can be seen as being very cold. But it's hard to see how such an approach has much merit for atoms in liquids or solids.
Re:Laser cooling is not new... (Score:5, Interesting)
Amazing lecture actually, he shoved about 20 balloons into a small liquid nitrogen flask throughout slowly arousing curiosity. Then whipped them out, frisbying them over the heads of students. The balloons were flat but began to expand even in mid air. Damn that was cool.
Anyway, at the time he explained that the current limit on their approach was being on earth. Essentially they trap the atoms inside a magnetic field and slowly uses momentum transfer from the photons to the atoms to cool them. Then once they have reached the limit of that approach they would expand the magnetic field so that the atoms now filled a larger space and tada you have traditional cooling.
The limit at this point was that they were unable to expand the magnetic field any further without losing its stability. To get round this he said the future aim was to do it in space and expand the field massively.
That was 2002, no idea where they have gotten with that technology now.