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A method for predicting non-equilibrium thermal expansion using steepest-entropy-ascent quantum thermodynamics
Ryo Yamada1, Michael R von Spakovsky2, William T Reynolds1
1Materials Science and Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States of America.
Summary
Steepest-entropy-ascent quantum thermodynamics (SEAQT) now models solid phases using pseudo-eigenstructures. This approach accurately predicts thermal expansion and lattice relaxations in metallic silver.
Area of Science:
- Quantum thermodynamics
- Solid-state physics
- Computational materials science
Background:
- Steepest-entropy-ascent quantum thermodynamics (SEAQT) offers a self-consistent framework for equilibrium and dynamic processes.
- Previous SEAQT applications were limited to gas-phase systems due to computational challenges with complex eigenstructures in condensed phases.
Purpose of the Study:
- Extend SEAQT modeling to solid phases by introducing a pseudo-eigenstructure.
- Validate the extended SEAQT framework by calculating the thermal expansion of metallic silver.
- Investigate SEAQT's capability to model irreversible processes in solids.
Main Methods:
- Constructed an anharmonic pseudo-eigenstructure for SEAQT in the solid phase.
- Applied the SEAQT framework to calculate the thermal expansion of metallic silver under equilibrium and non-equilibrium conditions.
- Simulated irreversible paths between equilibrium and non-equilibrium states.
Main Results:
- SEAQT with the pseudo-eigenstructure yielded reasonable predictions for equilibrium thermal expansion of silver.
- The model successfully predicted time-dependent lattice relaxations along irreversible paths.
- Demonstrated applicability to both equilibrium and dynamic processes in the solid phase.
Conclusions:
- The developed pseudo-eigenstructure effectively extends SEAQT to solid-phase modeling.
- SEAQT provides a robust method for analyzing thermal expansion and dynamic relaxations in solids.
- This advancement opens new avenues for studying complex thermodynamic processes in condensed matter.
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