102 citations · 241 across the 18 of their papers we have counts for
19 papers
QBism on Locality and Nonlocality
John B. DeBrota, Christopher A. Fuchs, Rüdiger Schack
Recently Pienaar (2026), building on work of Cavalcanti (2021), has shown that QBism cannot always assume distinct observers' quantum-measurement outcomes---say, of Wigner and his…
Consciousness, Quantum Mechanics, and the Limits of Scientific Objectivism
John B. DeBrota, Christian List
Consciousness and quantum mechanics are among the most puzzling phenomena studied in the sciences. Some scholars suggest they are related, though others think this claim commits a…
Robust Negativity in the Quantum-to-Classical Transition of Kerr Dynamics
Mohsin Raza, John B. DeBrota, Ariel Shlosberg +2
We quantify the quantum-to-classical transition of the single-mode Kerr nonlinear dynamics in the presence of loss. We establish three time scales that govern the dynamics, each wi…
A Heptalemma for Quantum Mechanics
John B. DeBrota, Christian List
We present a seven-pronged no-go result for quantum mechanics: a "heptalemma". It shows that seven initially plausible theses about physical reality are jointly inconsistent with t…
Bayesian rational agents in iterated quantum games
John B. DeBrota, Peter J. Love
We apply a Bayesian agent-based framework inspired by QBism to iterations of two quantum games, the CHSH game and the quantum prisoners' dilemma. In each two-player game, players h…
Synthesizing the Born rule with reinforcement learning
Rodrigo S. Piera, John B. DeBrota, Matthew B. Weiss +4
According to the subjective Bayesian interpretation of quantum theory (QBism), quantum mechanics is a tool that an agent would be wise to use when making bets about natural phenome…
Quantum Dynamics Happens Only on Paper: QBism's Account of Decoherence
John B. DeBrota, Christopher A. Fuchs, Ruediger Schack
QBism has long recognized quantum states, POVM elements, Kraus operators, and even unitary operations to be cut from the same cloth: They express aspects of an agent's belief syste…
Decoherence Limits the Cost to Simulate an Anharmonic Oscillator
Tzula B. Propp, Sayonee Ray, John B. DeBrota +2
We study how decoherence increases the efficiency with which we can simulate the quantum dynamics of an anharmonic oscillator, governed by the Kerr effect. As decoherence washes ou…
Quantum and Classical Bayesian Agents
John B. DeBrota, Peter J. Love
We describe a general approach to modeling rational decision-making agents who adopt either quantum or classical mechanics based on the Quantum Bayesian (QBist) approach to quantum…
Relating measurement disturbance, information and orthogonality
Yizhou Liu, John B. DeBrota
In the general theory of quantum measurement, one associates a positive semidefinite operator on a -dimensional Hilbert space to each of the possible outcomes of an arbitrar…
Born's rule as a quantum extension of Bayesian coherence
John B. DeBrota, Christopher A. Fuchs, Jacques L. Pienaar +1
The subjective Bayesian interpretation of probability asserts that the rules of the probability calculus follow from the normative principle of Dutch-book coherence: A decision-mak…
Respecting One's Fellow: QBism's Analysis of Wigner's Friend
John B. DeBrota, Christopher A. Fuchs, Ruediger Schack
According to QBism, quantum states, unitary evolutions, and measurement operators are all understood as personal judgments of the agent using the formalism. Meanwhile, quantum meas…
Discrete Wigner Functions from Informationally Complete Quantum Measurements
John B. DeBrota, Blake C. Stacey
Wigner functions provide a way to do quantum physics using quasiprobabilities, that is, "probability" distributions that can go negative. Informationally complete POVMs, a much you…
Lüders Channels and the Existence of Symmetric Informationally Complete Measurements
John B. DeBrota, Blake C. Stacey
The Lüders rule provides a way to define a quantum channel given a quantum measurement. Using this construction, we establish an if-and-only-if condition for the existence of a …
The Varieties of Minimal Tomographically Complete Measurements
John B. DeBrota, Christopher A. Fuchs, Blake C. Stacey
Minimal Informationally Complete quantum measurements, or MICs, illuminate the structure of quantum theory and how it departs from the classical. Central to this capacity is their…
FAQBism
John B. DeBrota, Blake C. Stacey
We answer several questions that have been Frequently Asked about QBism. These remarks (many of them lighthearted) should be considered supplements to more systematic treatments by…
Symmetric Informationally Complete Measurements Identify the Irreducible Difference between Classical and Quantum Systems
John B. DeBrota, Christopher A. Fuchs, Blake C. Stacey
We describe a general procedure for associating a minimal informationally-complete quantum measurement (or MIC) and a set of linearly independent post-measurement quantum states wi…
Negativity Bounds for Weyl-Heisenberg Quasiprobability Representations
John B. DeBrota, Christopher A. Fuchs
The appearance of negative terms in quasiprobability representations of quantum theory is known to be inevitable, and, due to its equivalence with the onset of contextuality, of ce…
A Quantum Information Geometric Approach to Renormalization
John B. DeBrota
This essay constitutes a review of the information geometric approach to renormalization developed in the recent works of Bény and Osborne as well as a detailed work-through of som…