Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spontaneous Symmetry Breaking and Dynamic Phase Transition in Monolayer
  Silicene   The (r3xr3)R30{\deg} honeycomb of silicene monolayer on Ag(111) was found to
undergo a phase transition to two types of mirror-symmetric boundary-separated
rhombic phases at temperatures below 40 K by scanning tunneling microscopy. The
first-principles calculations reveal that weak interactions between silicene
and Ag(111) drive the spontaneous ultra buckling in the monolayer silicene,
forming two energy-degenerate and mirror-symmetric (r3xr3)R30{\deg} rhombic
phases, in which the linear band dispersion near Dirac point (DP) and a
significant gap opening (150 meV) at DP were induced. The low transition
barrier between these two phases enables them interchangeable through dynamic
flip-flop motion, resulting in the (r3xr3)R30{\deg} honeycomb structure
observed at high temperature.

29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol