This extended 2nd edition includes a detailed description of the link between quantum photon states and the macroscopic electric field. It introduces treatment of electrons not only as quantum particles with wavelike behavior, but more fundamentally as fermions with their own unique operator algebra and distinguishable behavior from bosons (i.e. photons). Finally, it describes and analyzes the Quantum Point Contact, which is a simple nanoscopic structure omnipresent in all quantum fermion circuits, such as electron interferometry. weiterlesen