Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Microscopic quantum interference in excitonic condensation of
  Ta$_2$NiSe$_5$   The microscopic quantum interference associated with excitonic condensation
in Ta$_2$NiSe$_5$ is studied in the BCS-type mean-field approximation. We show
that in ultrasonic attenuation the coherence peak appears just below the
transition temperature $T_{\rm c}$ whereas in NMR spin-lattice relaxation the
rate rapidly decreases below $T_{\rm c}$; these observations can offer a
crucial experimental test for the validity of the excitonic condensation
scenario in Ta$_2$NiSe$_5$. We also show that the excitonic condensation
manifests itself in a jump of the heat capacity at $T_{\rm c}$ as well as in
softening of the elastic shear constant, in accordance with the second-order
phase transition observed in Ta$_2$NiSe$_5$.

29
The categories of this paper are: funct-an
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th