In 1924 Louis de Broglie introduced the concept of wave-particle duality: the Planck constant h relates the momentum p of a massive particle to its de Broglie wavelength λdB=h/p. The superposition principle is one of the main postulates of quantum mechanics: diffraction and interference phenomena are therefore predicted and have been observed on objects of increasing complexity, from electrons to neutrons and complex molecules. Beyond the early electron diffraction experiments, the observation of single-particle double-slit-like interference was a highly sought-after result, considered by Feynman as having in it the heart of quantum mechanics.
The single particle interference experiment was done for the first time, with electrons, in 1976 and a few years later, positron diffraction was first observed. However, an analog of the double-slit experiment has not been made on any antimatter system. Here I will present the first observation of quantum wave interference of single positrons.
This result is part of the QUPLAS (QUantum interference and gravitation with Positrons and LASers) program, to study CPT invariance and the Weak Equivalence Principle.
Marco Giulio Giammarchi