title: Minimal energy ensemble Monte Carlo algorithm for the partition function of fermions coupled to classical fields.
abstract: Models of noninteracting fermions coupled to auxiliary classical fields are relevant to the understanding of a wide variety of problems in many-body physics, e.g., the description of manganites, diluted magnetic semiconductors, or strongly interacting electrons on lattices. We present a flat-histogram Monte Carlo algorithm that simulates a statistical ensemble that allows one to directly acquire the partition function at all temperatures for such systems. The defining feature of the algorithm is that it utilizes the complete thermodynamic information from the full energy spectrum of noninteracting fermions available during sampling of the configuration space of the classical fields. We benchmark the method for the classical Ising and Potts models in two dimensions, as well as the Falicov-Kimball model describing itinerant electrons interacting with heavy ions.
authors.affiliation: Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań, Poland.
authors.forename: Przemysław R
authors.initials: PR
authors.lastname: Grzybowski
authors.affiliation: National Quantum Information Centre of Gdańsk, 81-824 Sopot, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Czekaj
authors.affiliation: Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Nogala
authors.affiliation: Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Ścibior
authors.affiliation: Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań, Poland.|ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.
authors.forename: Ravindra W
authors.initials: RW
authors.lastname: Chhajlany