Hardy's paradox

Note that the theory of weak measurement allows Hardy's paradox to be explained.

In Hardy's paradox a positron and an electron go down both arms of each of their interferometers.

Lucien Hardy is a theoretical physicist, known for his work on the foundation of quantum physics including Hardy's paradox, a thought experiment he devised in 1992.

Hardy's paradox is a thought experiment in quantum mechanics devised by Lucien Hardy in which a particle and its antiparticle may interact without annihilating each other.

Independently, a team of physicists from Japan reported in December, 2008, and published in March, 2009, that they were able to use joint weak measurement to observe a photonic version of Hardy's paradox.

Related to this, the research group of Aephraim Steinberg at the University of Toronto confirmed Hardy's paradox experimentally using joint weak measurement' of the locations of entangled pairs of photons.