Bertaina, G.2013-02-272013-02-272013-02-27201210.1063/1.4755827https://infoscience.epfl.ch/handle/20.500.14299/89889WOS:000310685500007We investigate the crossover from Bardeen-Cooper-Schrieffer (BCS) superfluidity to Bose-Einstein condensation (BEC) in a two-dimensional Fermi gas at T = 0 using the fixed-node diffusion Monte Carlo method. We calculate the equation of state and the gap parameter as a function of the interaction strength, observing large deviations compared to mean-field predictions. In the BEC regime our results show the important role of dimer-dimer and atom-dimer interaction effects that are completely neglected in the mean-field picture. We also consider the highly polarized gas and the competition between a polaronic and a molecular picture.BCS-BEC crossoverDiffusion Monte Carlolow dimensionalityBCS-BEC crossover in two dimensions: a Quantum Monte Carlo studytext::conference output::conference proceedings::conference paper