Strongly bound fermion pairs on a ring: A composite-boson approach

  title={Strongly bound fermion pairs on a ring: A composite-boson approach},
  author={Eloisa Cuestas and Cecilia Cormick},
  journal={Physical Review A},
Particles made of two fermions can in many cases be treated as elementary bosons, but the conditions for this treatment to be valid are nontrivial. The so-called “coboson formalism” is a powerful tool to tackle compositeness effects relevant for instance for exciton physics and ultracold atomic dimers. A key element of this theory is an ansatz for the ground state of N pairs, built from the single-pair ground state combined with the exclusion principle. We show that this ansatz can fail in one… 

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