Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effect of a Normal-State Pseudogap on Optical Conductivity in Underdoped
  Cuprate Superconductors   We calculate the c-axis infrared conductivity $\sigma_c(\omega)$ in
underdoped cuprate superconductors for spinfluctuation exchange scattering
within the CuO$_2$-planes including a phenomenological d-wave pseudogap of
amplitude $E_g$. For temperatures decreasing below a temperature $T^* \sim
E_g/2$, a gap for $\omega < 2E_g$ develops in $\sigma_c(\omega)$ in the
incoherent (diffuse) transmission limit. The resistivity shows 'semiconducting'
behavior, i.e. it increases for low temperatures above the constant behavior
for $E_g=0$. We find that the pseudogap structure in the in-plane optical
conductivity is about twice as big as in the interplane conductivity
$\sigma_c(\omega)$, in qualitative agreement with experiment. This is a
consequence of the fact that the spinfluctuation exchange interaction is
suppressed at low frequencies as a result of the opening of the pseudogap.
While the c-axis conductivity in the underdoped regime is described best by
incoherent transmission, in the overdoped regime coherent conductance gives a
better description.

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The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg