Volume 85, Number 3, February 2009
Article Number 30008
Number of page(s) 5
Section General
Published online 13 February 2009
EPL, 85 (2009) 30008
DOI: 10.1209/0295-5075/85/30008

The quantum refrigerator: The quest for absolute zero

Y. Rezek1, P. Salamon2, K. H. Hoffmann3 and R. Kosloff1

1   Fritz Haber Research Center for Molecular Dynamics, Hebrew University of Jerusalem - Jerusalem, 91904, Israel
2   Department of Mathematical Science, San Diego State University - San Diego, CA, 92182, USA
3   Physics Institute, Technical University of Chemnitz - Chemnitz, D-09107 Germany, EU

received 17 November 2008; accepted in final form 18 January 2009; published February 2009
published online 13 February 2009

The emergence of the laws of thermodynamics from the laws of quantum mechanics is an unresolved issue. The generation of the third law of thermodynamics from quantum dynamics is analysed. The scaling of the optimal cooling power of a reciprocating quantum refrigerator is sought as a function of the cold bath temperature as Tc $\rightarrow$ 0. The working medium consists of noninteracting particles in a harmonic potential. Two closed-form solutions of the refrigeration cycle are analyzed, and compared to a numerical optimization scheme, focusing on cooling toward zero temperature. The optimal cycle is characterized by linear relations between the heat extracted from the cold bath, the energy level spacing of the working medium and the temperature. The scaling of the optimal cooling rate is found to be proportional to Tc3/2 giving a dynamical interpretation to the third law of thermodynamics.

05.30.-d - Quantum statistical mechanics.
05.70.-a - Thermodynamics.
07.20.Pe - Heat engines; heat pumps; heat pipes.

© EPLA 2009