Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strong enhancement of the valley splitting in a 2D electron system in
  silicon   Using magnetocapacitance data, we directly determine the chemical potential
jump in a strongly correlated 2D electron system in silicon when the filling
factor traverses the valley gap at \nu=1 and \nu=3. The data yield a valley gap
that is strongly enhanced compared to the single-particle value and increases
LINEARLY with magnetic field. This result has not been explained by existing
theories.

12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th