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Atomic Gases at Negative Kinetic Temperature

A. P. Mosk
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Abstract

We show that thermalization of the motion of atoms at negative temperature is possible in an optical lattice, for conditions that are feasible in current experiments. We present a method for reversibly inverting the temperature of a trapped gas. Moreover, a negative-temperature ensemble can be cooled, reducing abs(T), by evaporation of the lowest-energy particles. This enables the attainment of the Bose-Einstein condensation phase transition at negative temperature.

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A. P. Mosk. 2005-07-04. Atomic Gases at Negative Kinetic Temperature. https://doi.org/10.1103/physrevlett.95.040403

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