Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum superpositions of "common-cause" and "direct-cause" causal
  structures   The constraints arising for a general set of causal relations, both
classically and quantumly, are still poorly understood. As a step in exploring
this question, we consider a coherently controlled superposition of
"direct-cause" and "common-cause" relationships between two events. We propose
an implementation involving the spatial superposition of a mass and general
relativistic time dilation. Finally, we develop a computationally efficient
method to distinguish such genuinely quantum causal structures from classical
(incoherent) mixtures of causal structures and show how to design experimental
verifications of the nonclassicality of a causal structure.

8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an