Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermoelectricity by Perfectly Conducting Channels in Quantum Spin Hall
  Systems   Thermoelectric transport of two-dimensional quantum spin Hall systems are
theoretically studied in narrow ribbon geometry. We find that at high
temperature electrons in the bulk states dominate. By lowering temperature, the
"perfectly conducting" edge channels becomes dominant, and a bulk-to-edge
crossover occurs. Correspondingly, by lowering temperature, the figure of merit
first decreases and then will increase again due to edge-state-dominated
thermoelectric transport.

33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc