Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Origin of the resistive anisotropy in the electronic nematic phase of
  BaFe$_2$As$_2$ revealed by optical spectroscopy   We perform, as a function of uniaxial stress, an optical-reflectivity
investigation of the representative 'parent' ferropnictide BaFe$_2$As$_2$ in a
broad spectral range, across the tetragonal-to-orthorhombic phase transition
and the onset of the long-range antiferromagnetic order (AFM). The infrared
response reveals that the $dc$ transport anisotropy in the orthorhombic AFM
state is determined by the interplay between the Drude spectral weight and the
scattering rate, but that the dominant effect is clearly associated with the
metallic spectral weight. In the paramagnetic tetragonal phase, though, the
$dc$ resistivity anisotropy of strained samples is almost exclusively due to
stress-induced changes in the Drude weight rather than in the scattering rate,
definitively establishing the anisotropy of the Fermi surface parameters as the
primary effect driving the $dc$ transport properties in the electronic nematic
state.

24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci