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Performance of reservoir discretizations in quantum transport simulations
Justin E Elenewski1, Gabriela Wójtowicz2, Marek M Rams2
1Biophysical and Biomedical Measurement Group, Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
The Journal of Chemical Physics
|October 2, 2021
Summary
Researchers explored how to best simulate quantum transport using finite electronic reservoirs. They found that optimizing the relaxation parameter is crucial for accurate continuum approximations, more so than discretization choices.
Area of Science:
- Quantum physics
- Computational condensed matter physics
Background:
- Quantum transport simulations frequently employ finite electronic reservoirs.
- Achieving the correct continuum limit with these reservoirs involves a balance between discretization and computational expense.
Purpose of the Study:
- To investigate the interplay between discretization and computational cost in extended reservoir simulations for quantum transport.
- To develop a method for estimating optimal relaxation parameters in finite reservoirs for many-body systems.
Main Methods:
- Analysis in the non-interacting limit, parameterizing different discretizations.
- Development of a method to estimate relaxation by controlling virtual transitions in Kramers turnover for current in many-body systems.
Main Results:
- Discretization choices have minimal impact on numerical costs for certain computational tools, especially in many-body tensor network simulations.
- The efficiency of discretizations varies with other numerical controls.
- The choice of relaxation parameter is critical for approximating the continuum limit.
Conclusions:
- Optimizing the relaxation parameter is more crucial than discretization for accurate quantum transport simulations with finite reservoirs.
- The developed method provides a reliable estimate for optimal relaxation in finite reservoirs.
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