Read about selection rules | 9 Discussions | Page 1

  1. S

    A Selection rules using Group Theory: many body

    Hello, I am newish in group theory so sorry if anything in the following is not entirely correct. In general, one can anticipate if a matrix element <i|O|j> is zero or not by seeing if O|j> shares any irreducible representation with |i>. I know how to reduce to IRs the former product but I...
  2. G

    I How can X-ray energy transitions be identified?

    Here is what I understand so far about x-ray energy transitions within an atom: The shells are divided up from lowest to highest as K, L, M, N, O, and so on. The X-ray associated with an electron dropping to a K shell is called K radiation. If the electron drops dropped from a shell directly...
  3. P

    I Selection rules for multiphoton vs single-photon ionization

    Question: For ionization of a homonuclear diatomic, how do the selection rules differ for a nonresonant 2-photon ionization process and a 1-photon ionization process?
  4. G

    I Could you provide me a selection rule?

    Hello. When I accessed to selection rule page in Wikipedia, I have a difficulty of how to use rules listed there. I'm now only concering electric dipole transition so column (E1) in the table there will be my only interests. Since I need to know whether transition is possible or not between...
  5. kq6up

    Trying to understand Selection Rules in Cohen-Tannoudji

    On the bottom half of page 249 Cohen-Tannoudji it talks about selection rules in terms of off diagonal elements of the matrix generated by ##\langle \phi _{ n^{ \prime },\tau ^{ \prime } } \mid \hat { B } \mid \phi _{ n,\tau } \rangle##. I thought all off diagonal matrix elements would be...
  6. C

    In an infinite quantum well, why Δn=0?

    I've been reading up a bit on semiconductor quantum wells, and came across a selection rule for an infinite quantum well that says that "Δn = n' - n = 0", where n' is the quantum well index of an excited electron state in the conduction band, and n is the index of the valence band state where...
  7. blue_leaf77

    Selection rules in electric dipole appoximation

    Some literatures say that the selection rule in electric dipole approx. for angular momentum ##\Delta j = 0,-1,1## some other say ##\Delta l = -1,1##. I follow the notation used in my references, despite the difference I think since j and l are both angular momenta which fulfill angular momentum...
  8. Z

    Selection Rules and Light with Orbital Angular Momentum

    When we first learn of selection rules for atomic transitions, we learn that electrons have to change between states that differ in angular momentum by at most 1ħ, because photons have 1 unit of spin angular momentum. However, photons can have arbitrarily high integer quantities of orbital...
  9. U

    Emission lines of calcium

    Homework Statement Strong emission lines from calcium were observed at ##422.7nm##, ##610.3nm##, ##612.3nm##, ##616.3nm##, ##1034.9nm##, from transitions between ##4s^2##, ##4s5s## and ##4s4p##. The transition of ##422.7nm## was also observed at absorption. The singlet-triplet splitting of...
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