Path integral Monte Carlo calculation of the momentum distribution of the homogeneous electron gas at finite temperature

• Published in: High energy density physics Vol. 30; pp. 13 - 20
• Main Authors: Militzer, B., Pollock, E.L., Ceperley, D.M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2019
• Subjects: Dense plasmas; First-principles simulations; Momentum distributions; Path integral Monte Carlo; Path integral Monte Carlo; First-principles simulations; Momentum distributions; Dense plasmas
• ISSN: 1574-1818; 1878-0563
• DOI: 10.1016/j.hedp.2018.12.004

Path integral Monte Carlo (PIMC) simulations are employed to calculate the momentum distribution of the homogeneous electron gas at finite temperature. Open paths are introduced to sample off-diagonal elements of the real-space density matrix. It is demonstrated how the restricted PIMC method can be extended to incorporate open paths in order to allow for the simulations in fermionic systems where a sign problem is present. The computed momentum distribution shows significant deviations from behavior of free fermions when strong correlations are present but agrees with predictions from variational methods.