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Tough Perturbation Question (At least for me)

  1. Mar 14, 2005 #1
    Consider a particle confined in a two dimensional square well with faces at x=0,a;y=0,a. The doubly degenerate eigenstates appear as Psinp=(2/a)sin(n(pi)x/a)sin(p(pi)x/a)
    Enp=E1(n^2 + p^2)

    What do these energies become under perturbation H'=10^-3E1sin((pi)x/a)?

    Help anyone? No idea how to solve this.
  2. jcsd
  3. Mar 14, 2005 #2


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    There's not too much advice to give,just apply the theory strictly.Identify the basis,compute the pertubation matrix and then write the system of equations.

  4. Mar 14, 2005 #3

    Tom Mattson

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    I agree, this is about as plug-and-chug as it gets. Ed, have you read the relevant material in your textbook? This is a straightforward exercise in time-independent degenerate perturbation theory.


    Here's a nice summary:
    Last edited: Mar 14, 2005
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