4 papers
What is special about the Kirkwood-Dirac distributions? Only they produce natural conditional expectations
Matéo Spriet, Christopher Langrenez, Raymond Brummelhuis +1
Among the many quasiprobability representations of quantum mechanics, the family of Kirkwood-Dirac (KD) representations has come to the foreground in recent years. Each such KD rep…
The Kirkwood-Dirac representation associated to the Fourier transform for finite abelian groups: positivity
Stephan De Bièvre, Christopher Langrenez, Danylo Radchenko
We construct and study the Kirkwood-Dirac (KD) representations naturally associated to the Fourier transform of finite abelian groups . We identify all pure KD-positive states a…
Convex roofs witnessing Kirkwood-Dirac nonpositivity
Christopher Langrenez, Stephan De Bièvre, David R. M. Arvidsson-Shukur
Given two observables and , one can associate to every quantum state a Kirkwood-Dirac (KD) quasiprobability distribution. KD distributions are like joint classical probabili…
Almost no experiments have classical Kirkwood-Dirac representations
Christopher Langrenez, Wilfred Salmon, Stephan De Bièvre +3
A central problem in quantum information is determining quantum-classical boundaries. In the quasiprobability framework, a state is called classical if it is represented by a quasi…