American Journal of Physics
Man-made quantum wells: A new perspective on the finite square-well problem
Robert M. Kolbas, N. Holonyak
Abstract
The observation of man-made quantum size effects is now possible due to advances in semiconductor technology. Interest in quantum-well heterostructures and superlattices has added a new dimension to both the application and perspective of the traditional discussion of a particle in a box. This paper addresses these new perspectives and presents in an elementary manner the techniques employed to model single and multiple square wells in semiconductors. A brief overview of semiconductor microlayer devices is followed by a discussion of the physics of quantum-well heterostructures. Since the behavior of these structures is described by the finite square well, a simple iterative technique to solve for the bound states of single or multiple (coupled) square wells is presented. The iterative technique is quite general and powerful, yet the physical ideas and the mathematics are straightforward and simple. Finally, computer simulation is employed to illustrate the interaction between multiple coupled wells; the results are compared with those obtained via the usual Kronig–Penney model.