2025/02/21 by Dornheim, Tobias, Moldabekov, Zhandos, Schwalbe, Sebastian +2 · 5 citations
#Chemical Physics (physics.chem-ph) #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas)
paper · doi:10.48550/arxiv.2502.15288
We combine the recent η-ensemble path integral Monte Carlo (PIMC) approach to the free energy [T.~Dornheim et al., Phys.~Rev.~B 111, L041114 (2025)] with a recent fictitious partition function technique based on inserting a continuous variable that interpolates between the bosonic and fermionic limits [Xiong and Xiong, J.~Chem.~Phys.~157, 094112 (2022)] to deal with the fermion sign problem. As a practical example, we apply our set-up to the warm dense uniform electron gas over a broad range of densities and temperatures. We obtain accurate results for the exchange--correlation free energy down to half the Fermi temperature, and find excellent agreement with the state-of-the-art parametrization by Groth et al.~[Phys.~Rev.~Lett.~119, 135001 (2017)]. Our work opens up new avenues for the future study of a host of interacting Fermi-systems, including warm dense matter, ultracold atoms, and electrons in quantum dots.