Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Microscopic derivation of transport coefficients and boundary conditions
  in discrete drift-diffusion models of weakly coupled superlattices   A discrete drift-diffusion model is derived from a microscopic sequential
tunneling model of charge transport in weakly coupled superlattices provided
temperatures are low or high enough. Realistic transport coefficients and novel
contact current--field characteristic curves are calculated from microscopic
expressions, knowing the design parameters of the superlattice. Boundary
conditions clarify when possible self-sustained oscillations of the current are
due to monopole or dipole recycling.

21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph