278 citations · 1.3k across the 11 of their papers we have counts for
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A purification postulate for quantum mechanics with indefinite causal order
Mateus Araújo, Adrien Feix, Miguel Navascués +1
To study which are the most general causal structures which are compatible with local quantum mechanics, Oreshkov et al. introduced the notion of a process: a resource shared betwe…
Experimental Verification of an Indefinite Causal Order
Giulia Rubino, Lee A. Rozema, Adrien Feix +5
Investigating the role of causal order in quantum mechanics has recently revealed that the causal distribution of events may not be a-priori well-defined in quantum theory. While t…
Quantum superpositions of "common-cause" and "direct-cause" causal structures
Adrien Feix, Časlav Brukner
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 cohe…
Exponential Communication Complexity Advantage from Quantum Superposition of the Direction of Communication
Philippe Allard Guérin, Adrien Feix, Mateus Araújo +1
In communication complexity, a number of distant parties have the task of calculating a distributed function of their inputs, while minimizing the amount of communication between t…
Causally nonseparable processes admitting a causal model
Adrien Feix, Mateus Araújo, Časlav Brukner
A recent framework of quantum theory with no global causal order predicts the existence of "causally nonseparable" processes. Some of these processes produce correlations incompati…
The simplest causal inequalities and their violation
Cyril Branciard, Mateus Araújo, Adrien Feix +2
In a scenario where two parties share, act on and exchange some physical resource, the assumption that the parties' actions are ordered according to a definite causal structure yie…
Quantum superposition of the order of parties as a communication resource
Adrien Feix, Mateus Araújo, Časlav Brukner
In a variant of communication complexity tasks, two or more separated parties cooperate to compute a function of their local data, using a limited amount of communication. It is kn…
Characterizing finite-dimensional quantum behavior
Miguel Navascues, Adrien Feix, Mateus Araujo +1
We study and extend the semidefinite programming (SDP) hierarchies introduced in [Phys. Rev. Lett. 115, 020501] for the characterization of the statistical correlations arising fro…
Witnessing causal nonseparability
Mateus Araújo, Cyril Branciard, Fabio Costa +3
Our common understanding of the physical world deeply relies on the notion that events are ordered with respect to some time parameter, with past events serving as causes for futur…
Maximal incompatibility of locally classical behavior and global causal order in multi-party scenarios
Ämin Baumeler, Adrien Feix, Stefan Wolf
Quantum theory in a global space-time gives rise to non-local correlations, which cannot be explained causally in a satisfactory way; this motivates the study of theories with redu…
Quantum circuits cannot control unknown operations
Mateus Araújo, Adrien Feix, Fabio Costa +1
One of the essential building blocks of classical computer programs is the "if" clause, which executes a subroutine depending on the value of a control variable. Similarly, several…