Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tunneling measurements of the coulomb pseudogap in a two-dimensional
  electron system in a quantizing magnetic field   We study the Coulomb pseudogap for tunneling into the two-dimensional
electron system of high-mobility (Al,Ga)As/GaAs heterojunctions subjected to a
quantizing magnetic field at filling factor $\nu \leq 1$.
  Tunnel current-voltage characteristics show that for the double maximum
observed in the tunnel resistance at $\nu \approx 1$ the pseudogap is linear in
energy with a slope that depends on filling factor, magnetic field, and
temperature. We give a qualitative account of the filling factor dependence of
the pseudogap slope and we confirm the recently reported appearance of another
relaxation time for tunneling at $\nu \approx 1$. For the tunnel resistance
peaks at $\nu=1/3$ and 2/3 a completely different behaviour of the
current-voltage curves is found and interpreted as manifestation of the
fractional gap.

34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex