Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Perspectives of microwave quantum key distribution in open-air   One of the cornerstones of quantum communication is the unconditionally
secure distribution of classical keys between remote parties. This key feature
of quantum technology is based on the quantum properties of propagating
electromagnetic waves, such as entanglement, or the no-cloning theorem.
However, these quantum resources are known to be susceptible to noise and
losses, which are omnipresent in open-air communication scenarios. In this
work, we theoretically investigate the perspectives of continuous-variable
open-air quantum key distribution at microwave frequencies. In particular, we
present a model describing the coupling of propagating microwaves with a noisy
environment. Using a protocol based on displaced squeezed states, we
demonstrate that continuous-variable quantum key distribution with propagating
microwaves can be unconditionally secure at room temperature up to distances of
around 200 meters. Moreover, we show that microwaves can potentially outperform
conventional quantum key distribution at telecom wavelength at imperfect
weather conditions.

11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs