Ab initio path integral Monte Carlo simulations of warm dense two-component systems without fixed nodes: Structural...

Area of Science:

• Computational physics
• Quantum mechanics
• Materials science

Background:

• Accurate simulation of warm dense matter is crucial for understanding extreme states of matter.
• The fermion sign problem poses a significant computational challenge for ab initio simulations.

Purpose of the Study:

• To present new ab initio path integral Monte Carlo (PIMC) results for structural properties of warm dense hydrogen and beryllium.
• To address the fermion sign problem in electronic thermal density matrix calculations.

Main Methods:

• Utilizing the recently proposed ξ-extrapolation method to mitigate the fermion sign problem.
• Performing extensive ab initio path integral Monte Carlo (PIMC) simulations.

Main Results:

• Achieved excellent agreement between PIMC results and exact direct PIMC reference data.
• Demonstrated the efficacy of the ξ-extrapolation method for warm dense matter simulations.

Conclusions:

• The developed methods allow for the study of light elements and material mixtures in the warm dense matter regime.
• These findings have direct relevance for astrophysics, material science, and inertial confinement fusion research.