A quantum mechanical theory for the scattering of low-energy atoms from incommensurate crystal surface layers

This dissertation reports a new theory for the scattering of low energy atoms off crystal surfaces. First, existence of the Moller wave operators is proven for the general case of inelastic scattering from both ordered and disordered crystal slabs. Next, a general time-independent inelastic scattering theory is developed, based on the use of the integral form of the Lippmann-Schwinger equation. This theory is then specialized to elastic scattering from crystal monolayers with multiple commensurate or incommensurate surface periodicities, and a practical numerical implementation of the elastic theory is developed. Finally, extensive validation of the scattering theory and its numerical implementation is presented, including a successful comparison to experimental results from the scattering of He from LiF(001)