Wednesday, January 21, 2015

What to do now?

Here are my suggestions. Feel free to add your own.

1) I think we need a beautiful graph showing the 3 (or 4) bound states all together on the same scale so we can really compare how they look and how far they extend outside the well.

2) Some \(I_{11}^m\) calculations for m=1, 2, 3 for some value of a.

3) Some nice plots of E vs q with the bandwidths and band gaps all worked out?

4) other stuff? what would you like to see?

Also, can someone do a lattice specific heat post (in response to question 2).

How about if we post stuff here and try to get this all done by Friday. Then we can start some new interesting things.

PS. Multiplying by c^2 to get away from mks units and into eV-A or eV-nm can be helpful. For example, for calculating k and kappa, one can multiply through by c to get:
\( \kappa = \sqrt{\frac{2mc^2(-E)}{\hbar^2 c^2}} \)

\( k = \sqrt{\frac{2mc^2(E+V_0)}{\hbar^2c^2}} \)
where,
\(mc^2 = 0.511 \times 10^6 \) eV
and
\(\hbar c = 1970\) eV-A

6 comments:

  1. I totally agree.

    I would recommend a 1 A wide well, like we discussed in class. What depth were we using?? Maybe someone can summarize the parameters.

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  2. I think that Chris had a well 250 eV deep. Nellie and Helen have a well 300 eV deep. Both 1 A wide. I would love to see more about either of those; k and kappa for each state...

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  4. What bandwidths does one get with a 1.8 A center to center distance. That would mean 0.8 A of V=0 between wells i think. (is that right?)
    Or maybe 1.5 A center to center would be better? What do you think?
    (all this with 1 A wide wells.)

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  5. Patrick and I did some calculations for the k and kappa values.
    I think we got kappa1=7.7 kappa2=6.42 kappa3 = 3.626
    Our k values were k1=2.51 k2=4.94 k3=7.25
    These are for the 300 eV well.

    We also did some work on finding the normalization constants.
    A1=1.26
    D1=18.39
    A2=1.23
    B2=-18.84
    A3=1.13
    D3=-6.17

    I think Patrick might put together some graphs with these values on mathematica later tonight.

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  6. good, but maybe can you change your definition of D by using \(D e^{-\kappa (x-b)}\) instead of \(D e^{-\kappa x}\)

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