Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

QM: Corrections to the energy

  1. Feb 12, 2009 #1
    1. The problem statement, all variables and given/known data
    Hi all.

    We are looking at a quantum mechanical system, where there is a perturbation H', so H = H0 + H', where H0 is the unperturbed Hamiltonian.

    The exact eigenenergies (i.e. the eigenenergies of H) are given by:

    E = V_0(1-\epsilon) \quad \tex{and}\quad E = V_0(1-\epsilon^2).

    So far so good. The eigenenergies of H0 (i.e. the unperturbed eigenenergies) are given by:

    E = V_0 \quad \tex{and}\quad E = V_0.

    The first order corrections to the eigenenergies of H0 are given by: [itex]E=0[/itex] and [itex]E=-\epsilon V_0[/itex].

    Here my question: How do I generally know which correction "belongs" to which unperturbed energy?

    My book is "Griffiths Intro to QM", so feel free to quote from there: The above example is exercise 6.9.

    Thanks in advance.

    Best regards,
    Last edited: Feb 12, 2009
  2. jcsd
  3. Feb 12, 2009 #2
    Ok, I answered this question myself. The energies are the same, so it doesn't matter which energy we add the constants to.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook