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Updated: May 18, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Demonstration of Jarzynski's equality in open quantum systems using a stepwise pulling protocol
1Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA.
We generalized Jarzynski's equality for quantum systems, linking mechanical work and free energy changes. This method uses stepwise pulling and measures fluctuations for experimental testing in complex systems.
Area of Science:
- Quantum thermodynamics
- Statistical mechanics
- Physical chemistry
Background:
- Jarzynski's equality relates non-equilibrium work to equilibrium free energy differences.
- Experimental verification in complex quantum systems remains challenging.
- Understanding free energy changes is crucial for quantum system characterization.
Purpose of the Study:
- To generalize Jarzynski's equality for quantum systems using a stepwise pulling protocol.
- To establish a theoretical framework for calculating free energy changes from work fluctuations.
- To propose methods for experimentally testing the generalized equality in many-body quantum systems.
Main Methods:
- Developed a theory based on a stepwise pulling protocol for quantum systems.
- Constructed work distribution functions from reaction coordinate fluctuations.
- Proposed two sets of equations to identify optimal pathways for free-energy calculations.
Main Results:
- Demonstrated that work distribution functions can be derived from fluctuations.
- Identified optimal pathways satisfying the principle of detailed balance.
- Successfully computed free-energy changes for a one-dimensional quantum harmonic oscillator.
Conclusions:
- The proposed theory provides a feasible method for measuring fluctuations to test Jarzynski's equality.
- This approach is applicable to complex many-body quantum systems like Bose-Einstein condensates.
- The findings bridge theoretical advancements with potential experimental validation in quantum thermodynamics.
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