Out-of-Equilibrium Fluctuation-Dissipation Bounds.

Area of Science:

• Condensed Matter Physics
• Quantum Thermodynamics
• Statistical Mechanics

Background:

• Established fluctuation-dissipation relations govern systems in equilibrium.
• Out-of-equilibrium systems present unique thermodynamic challenges.
• Quantum effects can invalidate classical thermodynamic relations.

Purpose of the Study:

• To establish a general inequality between charge current and its fluctuations.
• To extend fluctuation-dissipation relations to non-equilibrium conditions.
• To provide new constraints for quantum heat engines.

Main Methods:

• Theoretical analysis of weakly interacting coherent electronic conductors.
• Derivation of a novel fluctuation-dissipation bound.
• Investigation under stationary out-of-equilibrium conditions.

Main Results:

• A general inequality relating charge current and fluctuations is proven.
• The bound saturates at large temperature bias, offering insights for heat engines.
• The inequality holds where thermodynamic uncertainty relations fail due to quantum effects.

Conclusions:

• The new bound provides stronger constraints near thermovoltage.
• It offers a more comprehensive understanding of energy conversion in quantum systems.
• This work advances the study of non-equilibrium thermodynamics in electronic conductors.