Two interacting fermionic pairs in a 1D trap: a composite-boson approach

JIMÉNEZ, MARTÍN D.; CUESTAS, ELOISA; MAJTEY, ANA P.; CORMICK, CECILIA

Sao Paulo

Congreso; School on Quantum Chaos; 2023

International Center for Theoretical Physics, South American Institute for Fundamental Research

By using tools of the coboson formalism, we studied a 1D system consisting of fermions of two different species in a harmonic trap with tunable contact interaction. We prove that although the coboson ansatz does not provide a good description of the ground state of the system, since correlations between pairs can not be captured by the ansatz, this formalism provides tools to obtain numerical solutions based on the single-pair wavefunction. It allowed us to analyze properties of the system for finite values of interaction, such as correlations between particles and their statistical behavior. Our procedure is computationally inexpensive and illustrates how the coboson toolbox is useful for ultracold atom systems even in absence of condensation.