Thank you for your reply. So for a not intense EM field, a change of 1 is the best you can get, right? What do you mean by "or zero"? Can't you, in general, easily have a change of 1, without violating any conservation?Dr. Courtney said:Changes in total angular momentum of greater than one (or zero) require multiphoton events. Multiphoton events require much larger EM fields and usually result from a tuned and focused laser excitation.
kelly0303 said:Thank you for your reply. So for a not intense EM field, a change of 1 is the best you can get, right? What do you mean by "or zero"? Can't you, in general, easily have a change of 1, without violating any conservation?
Thank you! One more question, can we have transition for which ##\Delta l = 0##? Given that the photon has a spin of 1, and we conserve parity in EM interaction, I assume that we can only have ##\Delta l = \pm 1##. Is this true for all orders in an EM interactions (i.e. E1, E2, M1 and higher)? Also I assume we can have ##\Delta m = \pm 1##, but can we have ##\Delta m =0##? Given that the photon has as polarization components just ##\pm 1## but not 0, I assume that one can't have ##\Delta m =0##. Is that true? Thank you!Dr. Courtney said:Yes, single photon angular momentum changes of 1 are allowed. Sorry for the awkward, ambiguous grammar.
Indeed, the selection rule is ##\Delta l = \pm 1##, due to the spin of the photon.kelly0303 said:Thank you! One more question, can we have transition for which ##\Delta l = 0##? Given that the photon has a spin of 1, and we conserve parity in EM interaction, I assume that we can only have ##\Delta l = \pm 1##.
No. The quantization axis is not the same as the direction of propagation of the photon, so ##\Delta m =0## is allowed.kelly0303 said:Also I assume we can have ##\Delta m = \pm 1##, but can we have ##\Delta m =0##? Given that the photon has as polarization components just ##\pm 1## but not 0, I assume that one can't have ##\Delta m =0##. Is that true?
Things are a bit more complicated when you go beyond the dipole approximation. Seekelly0303 said:Is this true for all orders in an EM interactions (i.e. E1, E2, M1 and higher)? Thank you!
Transitions in diatomic molecules refer to the changes in energy levels or states of a molecule as it absorbs or emits electromagnetic radiation. These transitions are responsible for the absorption and emission of light by molecules, which can be observed in spectroscopy experiments.
Transitions in diatomic molecules occur when the molecule absorbs or emits a photon of electromagnetic radiation. This can happen through various mechanisms, such as electronic, vibrational, or rotational transitions, depending on the energy of the photon and the energy levels of the molecule.
Transitions in diatomic molecules are important because they provide information about the energy levels and structure of the molecule. By studying the wavelengths of light absorbed or emitted during transitions, scientists can determine the molecular properties and use this information for various applications, such as identifying substances or studying chemical reactions.
Several factors can influence transitions in diatomic molecules, including the energy of the absorbed or emitted photon, the molecular structure and geometry, and the temperature and pressure of the environment. These factors can affect the energy levels and vibrational or rotational states of the molecule, leading to different types of transitions.
Transitions in diatomic molecules are studied using spectroscopy techniques, which involve passing light through a sample of the molecule and analyzing the wavelengths of light absorbed or emitted. Different spectroscopy methods, such as infrared, ultraviolet-visible, or Raman spectroscopy, can provide information about different types of transitions and molecular properties.