An emergent quantized field enriches quantum many-body systems. We propose an antiparticle analog of the exciton in semimetals as collective mode interacting electron show that interband excitations are generally comprised both excitons and antiparticles excitons. These two stand for distinct modes semimetals, having different energies opposite conserved charges. The charge here is a quantity c...

One little-known area of chemistry is the chemistry of heavy main-group p elements, mostly metals and semimetals, in negative oxidation states. While the chemistry of Sn2+ and Sn4+, for example, is very well studied and we all learn about it very early in our education, not many people are aware of the fact that tin atoms can accept electrons and exhibit completely different reactivity when neg...