Title: Ground-state properties of unitary bosons: from clusters to matter,
Abstract: The properties of cold Bose gases at unitarity have been extensively
investigated in the last few years both theoretically and experimentally. In
this paper we use a family of interactions tuned to two-body unitarity and very
weak three-body binding to demonstrate the universal properties of both
clusters and matter. We determine the universal properties of finite clusters
up to 60 particles and, for the first time, explicitly demonstrate the
saturation of energy and density with particle number and compare with bulk
properties. At saturation in the bulk we determine the energy, density, two-
and three-body contacts and the condensate fraction. We find that uniform
matter is more bound than three-body clusters by nearly two orders of
magnitude, the two-body contact is very large in absolute terms, and yet the
condensate fraction is also very large, greater than 90%. Equilibrium
properties of these systems may be experimentally accessible through rapid
quenching of weakly-interacting boson superfluids.