14 papers
Modeling Authentic Research Trajectories: A Graph View of Research Ideation
Ruochen Li, Zhiyu Chen
The research idea in a published paper is rarely the project's initial idea. Between the two lies a closed-loop process in which researchers run experiments, derive insights, ident…
Passive realism in the presence of open system dynamics
James Fullwood, Boyu Yang, Weixiang Ye
We introduce the terminology \emph{passive realism} to encapsulate the scale-independent assumption that a physical system's pre-existing properties can be passively observed witho…
On the entropy of a pseudo-density matrix
James Fullwood, Boyu Yang
The pseudo-density matrix (PDM) formalism naturally extends the notion of density operator to the spatiotemporal domain. While PDMs are Hermitian and of unit trace, they admit nega…
Quantum information loss
James Fullwood, Wu-zhong Guo, Boyu Yang
We introduce a measure of information loss for any quantum process that may be modeled by a prepare-evolve-measure scenario: Alice prepares an ensemble of states that gets sent via…
Operational time-reversal symmetry for unital qubit channels
Ouyang Ting, James Fullwood, Zhen Wu
The Bayesian inverse of a quantum channel is a channel in the reverse direction of that yields time-symmetric correlations for sequential…
On Lorentzian symmetries of quantum information
James Fullwood, Vlatko Vedral, Edgar Guzmán-González
A foundational result in relativistic quantum information theory due to Peres, Scudo, and Terno, is that von Neumann entropy is not Lorentz invariant. Motivated by the "It from Qub…
On Dirac-type correlations
James Fullwood, Boyu Yang
Quantum correlations often defy an explanation in terms of fundamental notions of classical physics, such as causality, locality, and realism. While the mathematical theory underpi…
The Born rule as a natural transformation of functors
Boyu Yang, James Fullwood
In this work, we show that the quantum mechanical notions of density operator, positive operator-valued measure (POVM), and the Born rule, are all simultaneously encoded in the cat…
Partial transpose as a space-time swap
James Fullwood, Junxian Li
While the partial transpose operation appears in many fundamental results in quantum theory -- such as the Peres-Horodecki criterion for entanglement detection -- a physical interp…
Pindrop it! Audio and Visual Deepfake Countermeasures for Robust Detection and Fine Grained-Localization
Nicholas Klein, Hemlata Tak, James Fullwood +5
The field of visual and audio generation is burgeoning with new state-of-the-art methods. This rapid proliferation of new techniques underscores the need for robust solutions for d…
On small perturbations of coherent information
Zhen Wu, Zhihao Ma, James Fullwood
Quantum capacity quantifies the amount of quantum information that can be transmitted by a quantum channel with an arbitrary small probability of error. Mathematically, the quantum…
The spatiotemporal Born rule is quasiprobabilistic
James Fullwood, Zhihao Ma, Zhen Wu
Contrary to general relativity, quantum theory treats space and time in fundamentally different ways. In particular, while joint probabilities associated with spacelike separated m…
A diagrammatic formulation of local realism
James Fullwood
Given two parties performing experiments in separate laboratories, we provide a diagrammatic formulation of what it means for the joint statistics of their experiments to satisfy l…
Geometry from quantum temporal correlations
James Fullwood, Vlatko Vedral
In this work, we show how Euclidean 3-space uniquely emerges from the structure of quantum temporal correlations associated with sequential measurements of Pauli observables on a s…