7 research outputs found
Influence of the extent of the eigenstates of a system on the resonances formed through its coupling to a field
We examine resonances for two systems consisting of a particle coupled to a
massless boson's field. The field is the free field in the whole space. In the
first system, the particle is confined inside a ball. We show that besides the
usual energy levels of the particle, which have become complex through the
coupling to the field, other resonances are to be taken into account if the
ball's radius is comparable to the particle's Compton wavelength. In the second
system, the particle is in a finite-depth square-well potential. We study the
way the resonances' width depends on the extent of the uncoupled particle's
wave functions. In both cases, we limit ourselves to considering two levels of
the particle only
On hybrid states of two and three level atoms
We calculate atom-photon resonances in the Wigner-Weisskopf model, admitting
two photons and choosing a particular coupling function. We also present a
rough description of the set of resonances in a model for a three-level atom
coupled to the photon field. We give a general picture of matter-field
resonances these results fit into.Comment: 33 pages, 12 figure
On the consequences of the fact that atomic levels have a certain width
This note presents two ideas. The first one is that quantum theory has a
fundamentally perturbative basis but leads to nonperturbative states which it
would seem natural to take into account in the foundation of a theory of
quantum phenomena. The second one consists in questioning the validity of the
present notion of time. Both matters are related to the fact that atomic levels
have a certain width. This note is presented qualitatively so as to evidence
its main points, independently of the models on which these have been tested.Comment: 8 page