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Super cool atom thermometer: New, reliable ways of measuring extreme low temperatures

Date:
December 8, 2009
Source:
American Physical Society
Summary:
Physicists have devised a thermometer that can potentially measure temperatures as low as tens of trillionths of a degree above absolute zero.
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Physicists have developed a new thermometry method suitable for measuring temperatures of ultracold atoms.
Credit: Illustration: Alan Stonebraker

As physicists strive to cool atoms down to ever more frigid temperatures, they face the daunting task of developing new, reliable ways of measuring these extreme lows. Now a team of physicists has devised a thermometer that can potentially measure temperatures as low as tens of trillionths of a degree above absolute zero.

Their experiment is reported in the current issue of Physical Review Letters and highlighted with a Viewpoint in the December 7 issue of Physics.

Physicists can currently cool atoms to a few billionths of a degree, but even this is too hot for certain applications. For example, Richard Feynman dreamed of using ultracold atoms to simulate the complex quantum mechanical behavior of electrons in certain materials. This would require the atoms to be lowered to temperatures at least a hundred times colder than what has ever been achieved. Unfortunately, thermometers that can measure temperatures of a few billionths of a degree rely on physics that doesn't apply at these extremely low temperatures.

Now a team at the MIT-Harvard Center for Ultra-Cold Atoms has developed a thermometer that can work in this unprecedentedly cold regime. The trick is to place the system in a magnetic field, and then measure the atoms' average magnetization. By determining a handful of easily-measured properties, the physicists extracted the temperature of the system from the magnetization.

While they demonstrated the method on atoms cooled to one billionth of a degree, they also showed that it should work for atoms hundreds of times cooler, meaning the thermometer will be an invaluable tool for physicists pushing the cold frontier.


Story Source:

The above story is based on materials provided by American Physical Society. Note: Materials may be edited for content and length.


Journal References:

  1. A.M. Rey. The super cool atom thermometer. Physics, 2009; 2 (103) DOI: 10.1103/Physics.2.103
  2. David M. Weld, Patrick Medley, Hirokazu Miyake, David Hucul, David E. Pritchard, and Wolfgang Ketterle. Spin Gradient Thermometry for Ultracold Atoms in Optical Lattices. Physical Review Letters, 2009; 103 (245301) DOI: 10.1103/PhysRevLett.103.245301

Cite This Page:

American Physical Society. "Super cool atom thermometer: New, reliable ways of measuring extreme low temperatures." ScienceDaily. ScienceDaily, 8 December 2009. <www.sciencedaily.com/releases/2009/12/091207173626.htm>.
American Physical Society. (2009, December 8). Super cool atom thermometer: New, reliable ways of measuring extreme low temperatures. ScienceDaily. Retrieved April 26, 2015 from www.sciencedaily.com/releases/2009/12/091207173626.htm
American Physical Society. "Super cool atom thermometer: New, reliable ways of measuring extreme low temperatures." ScienceDaily. www.sciencedaily.com/releases/2009/12/091207173626.htm (accessed April 26, 2015).

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