PRA: Entropies and correlations of ultracold bosons in a lattice

Already only very few interacting ultracold atoms in a periodic potential provide the possibility study the all the facettes of the collective behavior that may emerge if there are many particles. The collective behavior of ultracold bosonic atoms in lattices can be categorized into three classes:

  1. the state in which all atoms behave alike and simultaneously occupy many wells of the periodic potential is called a superfluid
  2.  when, due to an increased laser intensity, the periodic potential becomes deeper and the repulsion between the particles is significant, the particles attain individuality by localizing in seperate wells of the lattice -- this state is called a Mott insulator.
  3. when there's multiple particles per minimum of the periodic confinement and the repulsion between them is very strong, the atoms localized in a single minimum of the potential do start to form a structure -- the state is then referred to as fermionized.

In our paper, we demonstrate that the collective behavior, 1.--3. of bosons in periodic potentials can be characterized unequivocally by, both, their correlation functions [panels (d), (e) and (i),(j)] and many-body entropy measures [panels (a)--(c) and (f)--(h)]. Read more at arXiv:1712.08792 and at PRA, 97, 043625 (2018).

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