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1.6 Tunneling

In classical mechanics a billiard ball bounces back when it hits the side of the billiard. In the quantum world it might actually "tunnel" through. Let me make this a little clearer. Classically a particle moving in the following potential would just be bouncing back and fourth between the walls. This can be easily seen from conservation of energy: The kinetic energy can not go negative, and the total energy is conserved. Where the potential is larger than the total energy, the particle cannot go. In quantum mechanics this is different, and particles can penetrate these classically forbidden regions, escaping from their cage.



© 1998 Niels Walet, UMIST
Email Niels.Walet@umist.ac.uk