LOCALIZATION OF RELATIVISTIC ELECTRONS IN A ONE-DIMENSIONAL DISORDERED SYSTEM

We address the question as to whether relativistic effects have any in fluence on localization phenomena in disordered systems. Starting from the Schrodinger and Dirac equations for Kronig-Penney potentials, we derive their discrete counterparts within the framework of the linear combination of atomic orbitals and tight-binding approaches, As a spec ific example we subsequently focus on substitutional binary alloys, We show that taking relativity into account leads to many important diff erences with respect to the results obtained in the non-relativistic a pproximation. The predicted behaviour of localization length can be ve ry relevant in several experimental contexts.