Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Properties of nano-graphite ribbons with zigzag edges -- Difference
  between odd and even legs --   Persistent currents and transport properties are investigated for the
nano-graphite ribbons with zigzag shaped edges with paying attention to system
length $L$ dependence. It is found that both the persistent current in the
isolated ring and the conductance of the system connected to the perfect leads
show the remarkable $L$ dependences. In addition, the dependences for the
systems with odd legs and those with even legs are different from each other.
On the persistent current, the amplitude for the cases with odd legs shows
power-low behavior as $L^{-N}$ with $N$ being the number of legs, whereas the
maximum of it decreases exponentially for the cases with even legs. The
conductance per one spin normalized by $e^2/h$ behaves as follows. In the even
legs cases, it decays as $L^{-2}$, whereas it reaches to unity for $L \to
\infty$ in the odd legs cases. Thus, the material is shown to have a remarkable
property that there is the qualitative difference between the systems with odd
legs and those with even legs even in the absence of the electron-electron
interaction.

37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int