What are negative absolute temperatures?

Jörn Dunkel, Stefan Hilbert

G. B. Furman, S. D. Goren, V. Meerovich +1 more

Jaime Wisniak

The concept of absolute temperature is developed on the basis of the second law. It is shown that although, in general, the absolute temperature can take only positive values, it can achieve negative values for particular cases where only a finite number of energy levels are available.

Ralph J. Tykodi

Xi Wang

The paper draws the concept of negative absoute temperature form thermodynamic system,studies the reationship between energy,absolute temperature and entropy in accordance with operating principle of laser and on the basis of which,the relativity of negative absoleete temperature is discussed.

Simon A. Weissman