Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electrical pump-and-probe study of spin singlet-triplet relaxation in a
  quantum dot   Spin relaxation from a triplet excited state to a singlet ground state in a
semiconductor quantum dot is studied by employing an electrical pump-and-probe
method. Spin relaxation occurs via cotunneling when the tunneling rate is
relatively large, confirmed by a characteristic square dependence of the
relaxation rate on the tunneling rate. When cotunneling is suppressed by
reducing the tunneling rate, the intrinsic spin relaxation is dominated by
spin-orbit interaction. We discuss a selection rule of the spin-orbit
interaction based on the observed double-exponential decay of the triplet
state.

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The categories of this paper are: math
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs