796 citations · 2.5k across the 22 of their papers we have counts for
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Classifying Causal Structures: Ascertaining when Classical Correlations are Constrained by Inequalities
Shashaank Khanna, Marina Maciel Ansanelli, Matthew F. Pusey +1
The classical causal relations between a set of variables, some observed and some latent, can induce both equality constraints (typically conditional independences) as well as ineq…
Uniqueness of noncontextual models for stabilizer subtheories
David Schmid, Haoxing Du, John H. Selby +1
We give a complete characterization of the (non)classicality of all stabilizer subtheories. First, we prove that there is a unique nonnegative and diagram-preserving quasiprobabili…
A structure theorem for generalized-noncontextual ontological models
David Schmid, John H. Selby, Matthew F. Pusey +1
It is useful to have a criterion for when the predictions of an operational theory should be considered classically explainable. Here we take the criterion to be that the theory ad…
Contextuality without access to a tomographically complete set
Matthew F. Pusey, Lídia del Rio, Bettina Meyer
The non-classicality of single quantum systems can be formalised using the notion of contextuality. But can contextuality be convincingly demonstrated in an experiment, without ref…
Anomalous weak values and contextuality: robustness, tightness, and imaginary parts
Ravi Kunjwal, Matteo Lostaglio, Matthew F. Pusey
Weak values are quantities accessed through quantum experiments involving weak measurements and post-selection. It has been shown that 'anomalous' weak values (those lying beyond t…
Experimentally bounding deviations from quantum theory in the landscape of generalized probabilistic theories
Michael D. Mazurek, Matthew F. Pusey, Kevin J. Resch +1
Many experiments in the field of quantum foundations seek to adjudicate between quantum theory and speculative alternatives to it. This requires one to analyze the experimental dat…
Is a time symmetric interpretation of quantum theory possible without retrocausality?
Matthew Leifer, Matthew Pusey
Huw Price has proposed an argument that suggests a time-symmetric ontology for quantum theory must necessarily be retrocausal, i.e. it must involve influences that travel backwards…
Can a quantum state over time resemble a quantum state at a single time?
Dominic Horsman, Chris Heunen, Matthew F. Pusey +2
Standard quantum theory represents a composite system at a given time by a joint state, but it does not prescribe a joint state for a composite of systems at different times. If a…
Algorithmic construction of local hidden variable models for entangled quantum states
Flavien Hirsch, Marco Túlio Quintino, Tamás Vértesi +2
Constructing local hidden variable (LHV) models for entangled quantum states is challenging, as the model should reproduce quantum predictions for all possible local measurements.…
Why protective measurement does not establish the reality of the quantum state
Joshua Combes, Christopher Ferrie, Matthew S. Leifer +1
"Protective measurement" refers to two related schemes for finding the expectation value of an observable without disturbing the state of a quantum system, given a single copy of t…
Logical pre- and post-selection paradoxes are proofs of contextuality
Matthew F. Pusey, Matthew S. Leifer
If a quantum system is prepared and later post-selected in certain states, "paradoxical" predictions for intermediate measurements can be obtained. This is the case both when the i…
Robust preparation noncontextuality inequalities in the simplest scenario
Matthew F. Pusey
Contextuality is the leading notion of nonclassicality for a single system. However, an experimental demonstration requires finding procedures that are operationally equivalent, wh…
An experimental test of noncontextuality without unwarranted idealizations
Michael D. Mazurek, Matthew F. Pusey, Ravi Kunjwal +2
To make precise the sense in which nature fails to respect classical physics, one requires a formal notion of classicality. Ideally, such a notion should be defined operationally,…
Verifying the quantumness of a channel with an untrusted device
Matthew F. Pusey
Suppose one wants to certify that a quantum channel is not entanglement-breaking. I consider all four combinations of trusted and untrusted devices at the input and output of the c…
Anomalous Weak Values Are Proofs of Contextuality
Matthew F. Pusey
The average result of a weak measurement of some observable can, under post-selection of the measured quantum system, exceed the largest eigenvalue of . The nature of weak m…
Theory-independent limits on correlations from generalised Bayesian networks
Joe Henson, Raymond Lal, Matthew F. Pusey
Bayesian networks provide a powerful tool for reasoning about probabilistic causation, used in many areas of science. They are, however, intrinsically classical. In particular, Bay…
Negativity and steering: a stronger Peres conjecture
Matthew F. Pusey
The violation of a Bell inequality certifies the presence of entanglement even if neither party trusts their measurement devices. Recently Moroder et. al. showed how to make this s…
Quantum Steering Ellipsoids
Sania Jevtic, Matthew F. Pusey, David Jennings +1
The quantum steering ellipsoid of a two-qubit state is the set of Bloch vectors that Bob can collapse Alice's qubit to, considering all possible measurements on his qubit. We provi…
Can different quantum state vectors correspond to the same physical state? An experimental test
Daniel Nigg, Thomas Monz, Philipp Schindler +7
A century on from the development of quantum theory, the interpretation of a quantum state is still discussed. If a physicist claims to have produced a system with a particular wav…
Quantum lost property: a possible operational meaning for the Hilbert-Schmidt product
Matthew F. Pusey, Terry Rudolph
Minimum error state discrimination between two mixed states ρand σcan be aided by the receipt of "classical side information" specifying which states from some convex decomposition…
On the reality of the quantum state
Matthew F. Pusey, Jonathan Barrett, Terry Rudolph
Quantum states are the key mathematical objects in quantum theory. It is therefore surprising that physicists have been unable to agree on what a quantum state truly represents. On…
Stabilizer notation for Spekkens' toy theory
Matthew F. Pusey
Spekkens has introduced a toy theory [Phys. Rev. A, 75, 032110 (2007)] in order to argue for an epistemic view of quantum states. I describe a notation for the theory (excluding ce…