The intellectual lure : quantum physics in devices -- The practical lure : the quest for a new switch -- First quantization -- Quantum chemistry : atoms to molecules -- Bonds to bands : molecules to solids -- Second quantization and field theory -- Interactions and Green's functions -- The transport menagerie -- Classical transport -- From classical to semiclassical transport -- Quantum transport: the nonequilibrium Green's function formalism -- Simple limits : the Landauer equation -- Classical Ohm's law : the Drude formula -- The vanishing act : electron tunneling -- Tunneling with an index : molecular signatures of tunneling -- Through band conduction -- Conduction in molecules