Two-fermion molecules in a one-dimensional harmonic trap

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

Roma

Conferencia; Young Italian Quantum Information Science Conference; 2020

Trieste Institute for Theoretical Quantum Technologies

Low-particle systems constitute a direct link between the physics of one or two bodies and the physics of many bodies. We study a system consisting of independent molecules formed bytwo distinguishable fermions that interact via a contact potential in an elongated harmonic trap (this was already experimentally achieved), so the system can effectively be considered as1D. We focus on the entanglement between the constituents of the molecule. By using an ansatz of composite bosons for the ground state, we analyze properties such as the condensatefraction, the occupancy numbers of the Schmidt modes, and the density profile of a particle both, when adding molecules to the system and when the interaction parameter between theconstituent fermions is modified. In the strongly attractive regime, the pair is maximally entangled and the molecules behave like ideal bosons (BECs). On the other hand, in the stronglyrepulsive regime, the system exhibits a finite but not maximum amount of entanglement. The fermionization phenomenon is also studied in this regime. Our analysis paves the way tothe exploration of 1D Fermi gases with an arbitrary number of pairs across the full interaction range.