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Potato21
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Homework Statement
A scanning tunneling microscope (STM) can precisely determine the depths of surface features because the current through its tip is very sensitive to differences in the width of the gap between the tip and the sample surface. Assume that in this direction the electron wave function falls off exponentially with a decay length of 0.124 nm - that is with C=8.06 nm-1. Determine the ratio of the current when the STM tip is 0.488 nm above a surface feature to the current when the tip is 0.516 nm above the surface.
Homework Equations
I honestly don't have any idea, the question appears foreign to me. If anything that the penetration depth formula n=(h bar)/sqrt(2m(U-E)) but I don't see how to use it. I'm completely lost
The Attempt at a Solution
I don't really understand what its about so I haven't attempted a solution. The textbook we're using (Knight) doesn't cover any questions like it either. Help!
Thank you in advance.