Electron states in modulated nanowires

A theory of electrons in modulated nanowires is presented. We show that these structures are radically different from plain nanowires and quantum-well structures in their electronic, optical, and transport properties. We find that thermionic emission experiments only measure an effective barrier height. It is shown that the polarization of intersubband transitions can be controlled. We also predict a type of longitudinal localization effect induced by lateral confinement and give a simple criterion for its occurrence. This places a lower limit on the radii of nanowires that might be useful for optoelectronic applications. Furthermore, its impact on resonant tunneling is demonstrated. (C) 2003 American Institute of Physics.