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Thermodynamics of Weakly Measured Quantum Systems
Jose Joaquin Alonso1, Eric Lutz1, Alessandro Romito2
1Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany.
Physical Review Letters
|March 12, 2016
Summary
We define quantum work and heat for continuously monitored quantum systems, extending thermodynamic laws to the quantum realm. This allows distinguishing quantum work from heat and controlling measurement effects.
Area of Science:
- Quantum thermodynamics
- Stochastic thermodynamics
- Quantum measurement theory
Background:
- Classical thermodynamics and stochastic thermodynamics provide frameworks for energy, work, and heat.
- Quantum systems exhibit unique behaviors like superposition and entanglement, requiring specialized thermodynamic definitions.
- Continuous monitoring of quantum systems introduces challenges in defining thermodynamic quantities due to measurement backaction.
Purpose of the Study:
- To introduce rigorous definitions of quantum work and heat for individual quantum trajectories.
- To extend the first and second laws of stochastic thermodynamics to the quantum domain.
- To explore the interplay between quantum work, heat, and measurement in driven quantum systems.
Main Methods:
- Development of definitions for work and heat applicable to coherent superpositions of energy eigenstates.
- Application of these definitions to a weakly measured driven two-level system.
- Utilizing quantum feedback control to mitigate detector backaction and analyze work statistics.
Main Results:
- Established definitions for work and heat along quantum trajectories valid for coherent states.
- Extended the first and second laws of stochastic thermodynamics to quantum systems.
- Demonstrated the ability to distinguish quantum work and heat contributions in a specific quantum system.
- Showcased the use of quantum feedback control for precise determination of work statistics.
Conclusions:
- The introduced definitions provide a robust framework for quantum stochastic thermodynamics.
- Continuous monitoring and feedback control are crucial for understanding energy exchange in quantum systems.
- This work lays the foundation for further exploration of thermodynamics in the quantum regime.
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