Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pauli spin blockade in cotunneling transport through a double quantum
  dot   We study spin correlation in a double quantum dot containing a few electrons
in each dot (around 10). Clear current rectification with negative differential
conductance is observed in the cotunneling regime, which is well explained by a
Pauli spin blockade. The current feature is discussed in connection with
exchange singlet-triplet splitting based on two simple models, one of which
takes coherent interdot coupling and the other incoherent interdot coupling
into account.

14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol