Electronic states at unrelaxed and relaxed GaAs (110) surfaces

We have shown that, using a general class of Hamiltonians, the transfer-matrix technique may be used to obtain exact solutions for the electronic states at any crystal surface bounded by semi-infinite bulk. This result is formally generalized as a theorem and is used to study the electronic states at a clean GaAs (110) surface. The calculation employs an empirical tight-binding Hamiltonian which realistically models the GaAs surface and allows meaningful comparison with both experiments and self-consistent pseudopotential calculations. Surface states are calculated for the clean (110) surface, and a variety of structural relaxations are studied.