Nobel prize to P. A. M. Dirac awarded in 1933. Co-winner E. Schrödinger "for the discovery of new productive forms of atomic theory''
Dirac, P.A.M.; The Quantum Theory of the Electron
Proc. Roy. Soc. A117 (1928) 610;
By employing for a point electron in an arbitrary electromagnetic field the simplest Hamiltonian which satisfies the requirements of both relativity and the general transformation theory of quantum mechanics, an explanation is obtained of all the "duplexity'' phenomena without further assumption. The spinning electron model devised to account for the observed duplexity may be regarded as true as a first approximation. The present theory, in fact, indicates that the electron will behave as though
possessing the magnetic moment assumed in the model, in addition to an electric moment, which is, however, imaginary and of doubtful physical significance (if any). The theory is applied to the case of motion in a central field, and the energy levels are shown to agree to a first approximation with those given by Darwin and by Pauli in which the spin of the electron is allowed for. (Science Abstracts. 1928. 1168. W.S.S.).
Discovery of the relativistic wave equation for the electron. Prediction of the magnetic moment of the electron.