The Thomas-Reiche-Kuhn sum rule is determined for an atom consisting of an arbitrary number of discrete, equally spaced eigenenergy levels. This generalization is consistent with a two-level atom and with a usually seen form of the sum rule involving the atomic ground state, and resolves an apparent paradox reported elsewhere.
Some new sum rules for atomic transition probabilities are developed; they are similar to the well-known rule of Kuhn, Reiche, and Thomas. They give, if unpolarized light is incident on any gaseous element in any given discrete energy level, the total absorption, excitation plus ionization, with various types of frequency weighting. The results are similar to those of Dirac and Harding, but are more general in that they apply to any discrete state of any atom, rather than to the ground state of hydrogen only. The method differs from that of Dirac and Harding.
The Thomas-Reiche-Kuhn (TRK) sum rule is a fundamental consequence of the position-momentum commutation relation for an atomic electron, and it provides an important constraint on the transitionmatrix elements for an atom. Here, we propose a TRK sum rule for electromagnetic fields which is valid even in the presence of very strong light- matter interactions and/or optical nonlinearities. While the standard TRK sum rule involves dipole matrix moments calculated between atomic energy levels (in the absence of interaction with the field), the sum rule here proposed involves expectation values of field operators calculated between general eigenstates of the interacting light-matter system. This sum rule provides constraints and guidance for the analysis of strongly interacting light-matter systems and can be used to test the validity of approximate effective Hamiltonians often used in quantum optics.
Abstract The Thomas–Reiche–Kuhn (TRK) sum rule is a fundamental consequence of the position–momentum commutation relation for an atomic electron, and it provides an important constraint on the transition matrix elements for an atom. Here, we propose a TRK sum rule for electromagnetic fields which is valid even in the presence of very strong light–matter interactions and/or optical nonlinearities. While the standard TRK sum rule involves dipole matrix moments calculated between atomic energy levels (in the absence of interaction with the field), the sum rule here proposed involves expectation values of field operators calculated between general eigenstates of the interacting light–matter system. This sum rule provides constraints and guidance for the analysis of strongly interacting light–matter systems and can be used to test the validity of approximate effective Hamiltonians often used in quantum optics.
A new class of sum rules in nonrelativistic scattering theory is obtained. By extending the concept of the Fredholm determinant to a local form defined at each space point x, a function with analytic properties analogous to the Fredholm determinant, but containing more information, is found. These rules assume the form of the power-moment problem and are valid in both quantum and classical mechanics.