Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum receiver for phase-shift keying at the single photon level   Quantum enhanced receivers are endowed with resources to achieve higher
sensitivities than conventional technologies. For application in optical
communications, they provide improved discriminatory capabilities for multiple
non-orthogonal quantum states. In this work, we propose and experimentally
demonstrate a new decoding scheme for quadrature phase-shift encoded signals.
Our receiver surpasses the standard quantum limit and outperforms all
previously known non-adaptive detectors at low input powers. Unlike existing
approaches, the receiver only exploits linear optical elements and on-off
photo-detection. This circumvents the requirement for challenging feed-forward
operations that limit communication transmission rates and can be readily
implemented with current technology.

5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
21
The categories of this paper are: adap-org