Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pressure and Inversion Symmetry Breaking Field Driven First Order Phase
  Transition and Formation of Dirac Circle in Perovskites   Through model Hamiltonian studies and first-principle electronic structure
calculations, we have examined the effect of inversion symmetry breaking (ISB)
field and hydrostatic pressure on the band topology of halide perovskites by
taking MAPbI$_3$ as a prototype. Our study shows that while hydrostatic
pressure induces normal to topological insulator continuous phase transition,
the ISB field makes it first order. The pressure smoothly reduces the normal
bandgap, and without ISB, the system achieves a gapless state before it
produces a non-trivial bandgap with inverted characters. The ISB field does not
stabilize the gapless state, and therefore, the discontinuity in the bandgap
with pressure gives rise to the first-order transition. Furthermore, in the
non-trivial phase, the ISB field forms an invariant surface Dirac circle in the
neighbourhood of TRIM, which is first of its kind. The circle is formed due to
interpenetration of Dirac cones resembling the band topology of AA-stacked
bilayer graphene.

22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys