Condensed Matter Seminar: Prof. Hong Ding, Institute of Physics
Title: Eureka: Novel Fermions in Solid Universe
Abstract: The universe, with a continuum space-time and Lorentz invariance, has only three possible types of fermions in theory, namely, Dirac, Weyl and Majorana fermions. In reality, only Dirac-type elementary particles have been discovered. While it is still under debate whether any elementary particle of Weyl or Majorana types exists, all three types of fermions have been proposed to exist as emergent quasiparticles in condensed matter systems, or the solid universe, which has discrete lattices without Lorentz invariance. Its 230 space groups in lattices can produce even more types of emergent fermions that are not allowed in the real universe. In this talk I will present our experimental discoveries of Weyl fermion, Majorana fermion and new fermions in the solid universe.