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Fourier-Matsubara series expansion for imaginary-time correlation functions
Panagiotis Tolias1, Fotios Kalkavouras1, Tobias Dornheim2,3
1Space and Plasma Physics-Royal Institute of Technology (KTH), SE-10044 Stockholm, Sweden.
The Journal of Chemical Physics
|May 8, 2024
Summary
A new Fourier-Matsubara series expansion for imaginary-time correlation functions is introduced. This method simplifies calculations and enhances quantum Monte Carlo data utilization in many-body physics.
Area of Science:
- Condensed Matter Physics
- Quantum Many-Body Theory
Background:
- Imaginary-time correlation functions are crucial in quantum many-body physics.
- Existing methods for analyzing these functions can be computationally intensive.
Purpose of the Study:
- To develop a novel series expansion for imaginary-time correlation functions.
- To provide a more efficient method for analyzing quantum simulation data.
- To explore the utility of imaginary-time domain in many-body physics.
Main Methods:
- Derivation of a Fourier-Matsubara series expansion.
- Generalization of the infinite Matsubara series to imaginary time.
- Application to density-density correlation functions using a finite-temperature self-consistent dielectric formalism.
Main Results:
- The derived expansion is consistent with known exact properties of imaginary-time correlation functions.
- The expansion significantly simplifies computations.
- New avenues for utilizing quantum Monte Carlo simulation data are opened.
Conclusions:
- The Fourier-Matsubara series expansion offers a powerful tool for analyzing imaginary-time correlation functions.
- This approach enhances the efficiency of computational methods in many-body physics.
- The imaginary-time domain is a valuable complementary perspective for studying quantum systems.
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