Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of three-photon bound states in a quantum nonlinear medium   Bound states of massive particles, such as nuclei, atoms or molecules,
constitute the bulk of the visible world around us. In contrast, photons
typically only interact weakly. We report the observation of traveling
three-photon bound states in a quantum nonlinear medium where the interactions
between photons are mediated by atomic Rydberg states. Photon correlation and
conditional phase measurements reveal the distinct bunching and phase features
associated with three-photon and two-photon bound states. Such photonic trimers
and dimers possess shape-preserving wavefunctions that depend on the
constituent photon number. The observed bunching and strongly nonlinear optical
phase are quantitatively described by an effective field theory (EFT) of
Rydberg-induced photon-photon interactions, consistent with the presence of a
substantial effective three-body force between the photons. These observations
demonstrate the ability to realize and control strongly interacting quantum
many-body states of light.

30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
1
The categories of this paper are: cs