Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-chiral spin frustration versus highly degenerate ferromagnetic state
  with local chiral degrees of freedom of an exactly solvable spin-electron
  planar model of inter-connected trigonal bipyramids   The frustration phenomenon in an exactly solvable spin-electron planar model
constituted by identical bipyramidal plaquettes is discussed within the
Toulouse's and dos Santos and Lyra's frustration concepts. It is shown that the
ground state of the model contains the unfrustrated spontaneously ordered
quantum ferromagnetic phase with local chiral degrees of freedom in the
electron sub-lattice and the disordered quantum one, where both the Ising and
electron sub-lattices are frustrated. The frustration of the latter sub-lattice
persists at finite temperatures, but only in the disordered region. It finally
vanishes at a certain frustration temperature. The reentrant behaviour of the
frustration in the electron sub-lattice with three consecutive frustration
temperatures due to a competition with the unfrustrated ferromagnetic spin
arrangement near the ground-state phase transition can also be observed.

11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga