Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase transition from a $d_{x^2-y^2}$ to $d_{x^2-y^2}+d_{xy}$
  superconductor   We study the phase transition from a $d_{x^2-y^2}$ to $d_{x^2-y^2}+d_{xy}$
superconductor using the tight-binding model of two-dimensional cuprates. As
the temperature is lowered past the critical temperature $T_c$, first a $
d_{x^2-y^2}$ superconducting phase is created. With further reduction of
temperature, the $ d_{x^2-y^2}+d_{xy}$ phase is created at temperature
$T=T_{c1}$. We study the temperature dependencies of the order parameter,
specific heat and spin susceptibility in these mixed-angular-momentum states on
square lattice and on a lattice with orthorhombic distortion. The
above-mentioned phase transitions are identified by two jumps in specific heat
at $T_c$ and $T_{c1}$.

13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom