Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamic Polarization and Relaxation of 75As Nuclei in Silicon at High
  Magnetic Field and Low Temperature   We present the results of experiments on dynamic nuclear polarization and
relaxation of 75As in silicon crystals. Experiments are performed in strong
magnetic fields of 4.6 T and temperatures below 1 K. At these conditions donor
electron spins are fully polarized, and the allowed and forbidden ESR
transitions are well resolved. We demonstrate effective nuclear polarization of
75As nuclei via the Overhauser effect on the time scale of several hundred
seconds. Excitation of the forbidden transitions leads to a polarization
through the solid effect. The relaxation rate of donor nuclei has strong
temperature dependence characteristic of Orbach process.

18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph