Super cool atom thermometer

Dec 07, 2009
Physicists have developed a new thermometry method suitable for measuring temperatures of ultracold atoms. 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 to a few billionths of a degree, but even this is too hot for certain applications. For example, Richard Feynman dreamed of using 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 field, and then measure the atoms' average magnetization. By determining a handful of easily-measured properties, the physicists extracted the 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.

More information: Spin Gradient Thermometry for Ultracold Atoms in Optical Lattices, David M. Weld, Patrick Medley, Hirokazu Miyake, David Hucul, David E. Pritchard, and Wolfgang Ketterle, Phys. Rev. Lett. 103, 245301 (2009) - Published December 07, 2009, Download PDF (free)

Source: American Physical Society

Explore further: Galaxy dust findings confound view of early Universe

add to favorites email to friend print save as pdf

Related Stories

Pushing the cold frontier in an orderly fashion

Sep 28, 2009

Physicists are continually reaching new lows as they reduce the temperatures of samples in their laboratories. But even nano-kelvins are not low enough to overcome the entropy (a measure of the disorder in ...

New way found to cool atoms and molecules

Aug 09, 2005

Physicists at The University of Texas say they've found a new technique for cooling atoms and molecules, allowing more effective quantum physics studies.

Recommended for you

Galaxy dust findings confound view of early Universe

Jan 31, 2015

What was the Universe like at the beginning of time? How did the Universe come to be the way it is today?—big questions and huge attention paid when scientists attempt answers. So was the early-universe ...

Seeking cracks in the Standard Model

Jan 30, 2015

In particle physics, it's our business to understand structure. I work on the Large Hadron Collider (LHC) and this machine lets us see and study the smallest structure of all; unimaginably tiny fundamental partic ...

Building the next generation of efficient computers

Jan 29, 2015

UConn researcher Bryan Huey has uncovered new information about the kinetic properties of multiferroic materials that could be a key breakthrough for scientists looking to create a new generation of low-energy, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.