Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Landau Cooling in Metal-Semiconductor Nanostructures   An electron-cooling principle based on Landau quantization is proposed for
nanoscale conductor systems. Operation relies on energy-selective electron
tunneling into a two-dimensional electron gas in quantizing magnetic fields.
This quantum refrigerator provides significant cooling power (~1 nW at a few K
for realistic parameters) and offers a unique flexibility thanks to its
tunability via the magnetic-field intensity. The available performance is only
marginally affected by nonidealities such as disorder or imperfections in the
semiconductor. Methods for the implementation of this system and its
characterization are discussed.

10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph