Bertaina, G.Giorgini, S.2011-03-162011-03-162011-03-16201110.1103/PhysRevLett.106.110403https://infoscience.epfl.ch/handle/20.500.14299/65373WOS:000288450800003We 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. Results on Tan's contact parameter associated with short-range physics are also reported along the BCS-BEC crossover.2 DimensionsBose CondensationStatetext::journal::journal article::research article