Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photonic ferromagnetic-like spontaneous mode-locking phase transition
  with replica symmetry breaking in multimode Nd:YAG laser   The recent reports of the replica symmetry breaking (RSB) phenomenon in
photonic experiments [1-5] boosted the understanding of the role of disorder in
multimode lasers, as well as helped to settle enlightening connections [6-13]
with the statistical physics of complex systems. RSB manifests when
identically-prepared system replicas reach distinct states, yielding different
measures of observable quantities [14]. Here we demonstrate the RSB in the
spontaneous mode-locking regime of a conventional multimode Nd:YAG laser in a
closed cavity. The underlying mechanism is quite distinct from that of the RSB
spinglass phase in cavityless random lasers with incoherently-oscillating
modes. Here, a specific nonuniform distribution of the gain takes place in each
pulse, and frustration is induced since the coherent oscillation of a given
subset of longitudinal modes dominates and simultaneously inhibits the others.
Nevertheless, when high losses are introduced only the replica-symmetric
amplified stimulation emission is observed. We therefore suggest that the RSB
transition can be used as an identifier of the threshold in standard multimode
lasers, as recently proposed and demonstrated for random lasers [1,2].

7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga