The physicists F. Bloch, R. Peierls, and A. Wilson, mainly, created the modern solid state theory. Their theory describes the propagation of waves of electrons through the periodical potentials formed by the atoms in a crystal. The theory let understood the electrical behaviour of the conductors, of the insulators, and of the semiconductors.
The devices made from semiconductors substituted the thermionic high vacuum valves. The solid state electronics was born. The solid state devices can operate at frequencies of some hundred megahertz. At those frequencies the high vacuum valves can not operate. The technology of fabrication of the solid state devices was benefited with the new technologies of purification and controlled doping of semiconductor materials.
The Bell laboratories and another centers of research investigated and made solid state devices, during the second world war and after it. To do that, they created groups of physicists dedicated exclusively to the study of the solid state physics. Their presidents, also physicists, understood that to learn how to manipulate atom by atom could bring great benefits to the industry.
The technology based on the manipulation of atom by atom, and electron by electron, the physicists have no constructed them yet. The invention of the transistor is the closest intent. The physicists J. Bardeen, W. Shockley, and W. Brattain, from the Bell laboratories, invented it at the end of 1947. This device substituted the triode of de Forest in operation and capabilities. Its functions are the same, but the space that it occupies and its physical characteristics are not. The device application potential is enormous.
The physics of the transistor is described by the quantum mechanics. The interpretation of the transistor behaviour is the Shockley effect. The electrons and the holes can fluid, by diffusion, in mutual presence. Shockley called this phenomenon injection of minority carriers. The understanding of this phenomenon, given by the quantum mechanics, is the key for the development of this sort of dispositives.
The transistor allowed to develop, besides other scientific apparatuses, the computater. And of course, the computation as a scientific discipline.