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How can a temperature of 100 pK be measured?

  1. Feb 29, 2012 #1
    I´ve read that a temperature of 100 pK has been reached by scientists. But how can they measure such a low temperature? And achieve that level of accuracy?
  2. jcsd
  3. Feb 29, 2012 #2
  4. Feb 29, 2012 #3


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    Hope this helps you as well.
  5. Mar 1, 2012 #4
    Note that in this case they cooled down an old-fashioned lump of metal (Rhodium) using an old-fashioned dilfridge and (nuclear) adiabatic demagnetizatoin. Cooling atoms in an optical trap is a different ballgame.

    The original publications seem to be these here (stupidly, there is no link to this on their web site!!!)

    T. A. Knuuttila, J. T. Tuoriniemi, and K. Lefmann
    Relaxation of Polarized Nuclei in Superconducting Rhodium
    Phys. Rev. Lett. 85, 2573–2576 (2000)


    J.T Tuoriniemi and T.A Knuuttila
    Nuclear cooling and spin properties of rhodium down to picokelvin temperatures

    Physica B: Condensed Matter
    Volume 280, Issues 1–4, 11 May 2000, Pages 474–478

    http://dx.doi.org/10.1016/S0921-4526(99)01839-6 [Broken]

    From the second publication:
    I just love the fact that they consider 0.3mK "relatively high temperature". Compared to 100pK it's almost tropical.
    Last edited by a moderator: May 5, 2017
  6. Mar 1, 2012 #5


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    Interesting, I did not realize condensed matter had been cooled down that low.
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