Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Zero-Bias Anomaly in Quantum Wires   Undoped GaAs/AlGaAs heterostructures have been used to fabricate quantum
wires in which the average impurity separation is greater than the device size.
We compare the behavior of the Zero-Bias Anomaly against predictions from Kondo
and spin polarization models. Both theories display shortcomings, the most
dramatic of which are the linear electron-density dependence of the Zero-Bias
Anomaly spin-splitting at fixed magnetic field B and the suppression of the
Zeeman effect at pinch-off.

28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys