Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hidden nonmacrorealism: reviving the Leggett-Garg inequality with
  stochastic operations   The Leggett-Garg inequality (LGI) distinguishes nonmacrorealistic channels
from macrorealistic ones by constraining the experimental outcomes of the
underlying system. In this work, we propose a class of channels which,
initially, cannot violate the LGI (in the form of the temporal Bell inequality)
but can violate it after the application of stochastic pre- and post-
operations (SPPOs). As a proof-of-principle experiment, we demonstrate the
stochastic pre- and post- operations in an amplitude-damping channel with
photonic qubits. We denote the above phenomenon as hidden nonmacrorealistic
channels. We also discuss the relationship between this hidden
nonmacrorealistic channels (in terms of the temporal Clauser-Horne-Shimony-Holt
(CHSH) inequality) and the strongly nonlocality-breaking channel, which breaks
the hidden spatial CHSH nonlocality for arbitrary states. In general, if the
channel satisfies hidden nonmacrorealism, it is not a strongly CHSH
nonlocality-breaking channel.

3
The categories of this paper are: physics
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an