Recent content by Flenzil

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    Double delta well separated by a delta barrier

    So just in case people find this and want an answer. Yes, this is right and by "algebraic equations" the question didn't mean analytic so a relation that can be solved graphically is fine. Also, if you find that the odd solution ignores the central delta function completely, then you're headed...
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    Double delta well separated by a delta barrier

    I've been trying to solve it graphically but then I need values for \beta,\gamma and a and the functions change drastically depending on the values of these. I'm also unsure about this solution since it's currently: Be^{kx} for x<-a De^{2ka}(\frac{2k}{\gamma}-1)e^{kx}+De^{-kx} for -a<x<0...
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    Double delta well separated by a delta barrier

    The question wants algebraic solutions for E though. Although I'm not sure if this forbids a power series.
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    Double delta well separated by a delta barrier

    Well, I get C=De^{2ka}(\frac{2k}{\gamma}-1) as before Which I put into k=\frac{\beta}{2}\frac{D+C}{D-C} Which comes out with k=\frac{\beta}{2}\frac{1+e^{2ka}(\frac{2k}{\gamma}-1)}{1-e^{2ka}(\frac{2k}{\gamma}-1)} I'm having a hard time solving this for k, almost every term has a k in it...
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    Double delta well separated by a delta barrier

    I understand that if this were a non-delta well, I could compare k=\sqrt{-E} at the V=0 portion to \kappa =\sqrt{E+V_0} inside the well by forming an equation of k as a function of \kappa and finding the intersect of the two functions. But here that isn't possible here because there is no...
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    Double delta well separated by a delta barrier

    Ok, going through the calculations again, I've arrived at 3 equations for k, 1 for each boundary: For even symmetry Boundary 1: k=-k\frac{De^{ka}-Ce^{-ka}}{De^{ka}+Ce^{-ka}} +\gamma Boundary 2: k=\frac{\beta}{2} \frac{D+C}{D-C} Boundary 3: k=-k\frac{De^{ka}-Ce^{-ka}}{De^{ka}+Ce^{-ka}}...
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    Double delta well separated by a delta barrier

    Yes. Yes it should. If I use the differential continuity at the barrier I come up with a different relation between C and D: D=C\frac{2+\beta/k}{2-\beta/k} These seems at odds with the relation from the first well: C=D(\frac{2k}{\gamma}-1)e^{2ka} Mathmatically they both seem correct but...
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    Double delta well separated by a delta barrier

    So doing that, I get C=D\frac{2k}{\gamma} e^{2ka} (\frac{2k}{\gamma}-1) from the first well G=F\frac{2k}{\gamma} e^{2ka} (\frac{2k}{\gamma}-1) from the second well And then I use these with C+D=F+G from the barrier to get: D=F and C=G So that I have: Be^{kx} for x<-a...
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    Double delta well separated by a delta barrier

    I know that but I was trying to solve it generically first because I don't understand what happens to an exponential at a barrier. I know that for a traveling wave, it would exponentially decrease throughout the barrier until it got to the other side with a lower amplitude. But if it's already...
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    Double delta well separated by a delta barrier

    Homework Statement Consider a one-dimensional time-independent Schrodinger equation for an electron in a double quantum well separated by an additional barrier. The potential is modeled by: V (x) = -γδ(x - a) -γδ(x + a) + βδ(x) Find algebraic equations which determine the energies (or...
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