Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Liouville equation for systems which exchange particles with
  reservoirs: transport through a nano-device   A Redfield-like Liouville equation for an open system that couples to one or
more leads and exchanges particles with them is derived. The equation is
presented for a general case. A case study of time-dependent transport through
a single quantum level for varying electrostatic and chemical potentials in the
leads is presented. For the case of varying electrostatic potentials the
proposed equation yields, for the model study, the results of an exact
solution.

32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol