Die neurologischen Störungen bei Geisteskrankheiten

Quantum field theory of optical birefringence phenomena I. Linear and nonlinear optical rotation

“…In particular, if the /8-matrix is used it is unnecessary to grapple with the problem of constructing phenomenological equations to represent the process. For example, a semi-classical description of optical rotation could begin by calculating the magnetic dipole induced by a fluctuating electric field at a molecule (Rosenfeld 1928): this procedure does work but its extension to nonlinear processes is difficult and not always possible. The second advantage of the /8-matrix formalism is th at it is fitted to the type of observation th at one normally performs inasmuch as the interaction potential is taken to operate significantly only for a short time long after the system has been prepared and long before an observation is made.…”