Brueckner G -matrix approach to two-dimensional Fermi gases with finite-range attractive interactions

Two-dimensional spin-1/2 fermions with the finite-range interaction are theoretically studied. Characterizing the attractive interaction in terms of the scattering length and the effective range, we discuss the finite-range effects on the ground-state properties in this system. The Brueckner $G$-matrix approach is employed to analyze the finite-range effects on an attractive Fermi-polaron energy and the equation of state throughout the BEC-BCS crossover in two dimensions, which can be realized in the population-imbalanced and -balanced cases between two components, respectively. The analytical formulae for these ground states obtained in this study would be useful for understanding many-body phenomena with finite-range interactions in low-dimensional systems.