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Tunneling through a tex2html_wrap_inline420 function potential: as Seen in Solver Scenario 5

 

   figure161
Figure 3: Dirac tex2html_wrap_inline420 potential, strength D

As we discussed in class, in all cases where the potential is finite, the derivatives of the wave functions for the pure energy states, tex2html_wrap_inline592 , remain continuous across all boundaries.

If the potential V(x) contains a tex2html_wrap_inline420 function at the point x=a of strength D, tex2html_wrap_inline602 , then the potential is no longer finite at the point x=a, and there is a discontinuity in the slope. The tex2html_wrap_inline420 function, however is not strong enough to generate a discontinuity in the wave function itself.

As we will show in lecture on Thursday, this discontinuity has magnitude

  equation170

where tex2html_wrap_inline608 is the solution to the right of the tex2html_wrap_inline420 function (x;SPMgt;a) and tex2html_wrap_inline614 is the solution to the left of the tex2html_wrap_inline420 function (x;SPMlt;a). We use tex2html_wrap_inline620 in the expression (2) because it does not matter which part of the solution one uses for tex2html_wrap_inline620 ( wave function is continuous at a: tex2html_wrap_inline626 ).





Prof. Tomas Alberto Arias
Fri Apr 25 11:25:10 EDT 1997