Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hanbury-Brown and Twiss bunching of phonons and of the quantum depletion
  in a strongly-interacting Bose gas   We report the realisation of a Hanbury-Brown and Twiss (HBT)-like experiment
with a gas of strongly interacting bosons at low temperatures. The regime of
large interactions and low temperatures is reached in a three-dimensional
optical lattice and atom-atom correlations are extracted from the detection of
individual metastable Helium atoms after a long free-fall. We observe a HBT
bunching in the non-condensed fraction of the gas whose properties strongly
deviate from the HBT signals expected for non-interacting bosons. In addition,
we show that the measured correlations reflect the peculiar quantum statistics
of atoms belonging to the quantum depletion and of the Bogoliubov phonons,
i.e., of collective excitations of the many-body quantum state. Our results
demonstrate that atom-atom correlations provide information about the quantum
state of strongly-interacting particles, extending the interest of HBT-like
experiments beyond the case of non-interacting particles.

12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics