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A quantum violation of the second law?
1Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA.
Physical Review Letters
|February 21, 2006
Summary
This study resolves apparent thermodynamic violations by showing that the work needed to couple an atom to a zero-temperature bath exceeds any energy extracted, upholding the second law of thermodynamics.
Area of Science:
- Thermodynamics
- Quantum Mechanics
- Statistical Mechanics
Background:
- An apparent violation of the second law of thermodynamics arises when attempting to extract work from a zero-temperature bath using an excited atom.
- This phenomenon is often misinterpreted, overlooking the energy cost associated with coupling the atom to the bath.
Purpose of the Study:
- To investigate the apparent violation of the second law of thermodynamics in systems coupled to zero-temperature baths.
- To quantitatively determine the work required for coupling and the energy extractable from the system.
Main Methods:
- Analytical calculation of mean oscillator energy for an oscillator coupled to a bath using the single relaxation time model.
- Explicit, closed-form calculation of the minimum work required to couple the oscillator to the bath.
Main Results:
- The mean oscillator energy was calculated for the specified model.
- The minimum work required for coupling was determined to be consistently greater than the mean oscillator energy.
Conclusions:
- The energy cost of coupling an atom to a zero-temperature bath inherently exceeds the extractable work.
- This confirms that no violation of the second law of thermodynamics occurs in such systems.
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