Alexandre Tkatchenko

Two protons, two positrons, and four electrons: Covalent bond with van der Waals characteristics

Classifying interactions is key in the physical sciences, and bonding mechanisms in matter-antimatter systems remain particularly enigmatic. Here, we focus on a paradigmatic example of positronium hydride (PsH) dimer composed of two protons, two positrons, and four electrons, who...

Repulsive inverse-distance interatomic interaction from many-body quantum electrodynamics

Interactions between objects can be classified as fundamental or emergent. Fundamental interactions are either extremely short-range or decay inversely with the separation distance, such as the Coulomb potential between charges or the gravitational attraction between masses. In c...