Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strictly In-Plane Vortex-like Excitations in Pseudogap Region of
  Underdoped $La_{2-x}Sr_xCuO_4$ Single Crystals   Nernst effect has been measured for an underdoped and an optimally doped
$La_{2-x}Sr_xCuO_4$ single crystal with the magnetic field applied along
different directions. For both samples, when $H \|$ c, a significant Nernst
voltage appears above $T_c$ and keeps measurable up to a high temperature (100
K) as reported by Xu et al.[ Nature 406, 486(2000) ]. However, when $H \|$ a-b
plane the Nernst signal drops below the noise level quickly above $T_c$ for the
underdoped sample. Moreover, the in-plane Nernst data with field at different
angles shows a nice scaling behavior with the c-axis component of the field.
All these give strong indication for strictly in-plane vortex-like excitations
in pseudo-gap region.

31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics