Section 9.9: Exploring Wave Packet Scattering

 

Please wait for the animation to completely load.

Step Up:

Animation 1

Animation 2

Animation 3

Animation 4

Animation 5

Animation 6

Barrier:

Animation 1

Animation 2

Animation 3

Animation 4

Animation 5

Animation 6

Well:

Animation 1

Animation 2

Animation 3

Animation 4

Animation 5

Animation 6

This Exploration shows the same initial Gaussian wave packet incident on either a step up in potential energy, a potential energy barrier, or a potential energy well.  The animations successively increase the step/barrier height and well depth.  Shown in the table are the probabilities that the wave packet can be found in the various regions.7 In the animation, ħ = 2m = 1.

  1. For the step up animations, what happens to the packet as E increases?  What do you notice about how the wave function behaves in the two regions as a function of E? Make a reasonable estimate for how the transmission coefficient behaves as a function of E.

  2. For the barrier animations, what happens to the packet as E increases?  What do you notice about how the wave function behaves in the three regions as a function of E?  Make a reasonable estimate for how the transmission coefficient behaves as a function of E. What happens to the part of the wave function in the barrier?

  3. For the well animations, what happens to the packet as E increases?  What do you notice about how the wave function behaves in the three regions as a function of E?  Make a reasonable estimate for how the transmission coefficient behaves as a function of E.  What happens to the part of the wave function in the well?

___________________

7The problem of wave packets incident on a step up in potential energy is discussed by R. Shankar in Principles of Quantum Mechanics, Plenum Press (1994).

 

 

© 2006 by Prentice-Hall, Inc. A Pearson Company