2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101647We present a viewpoint of the transport process in quantum cascade laser structures in which spatial transport of charge through the structure is a property of coherent quantum-mechanical wavefunctions. In contrast, scattering processes redistribute particles in energy and momentum but do not directly cause spatial motion of charge.6 pages, 5 figures included in tex, to appear in Physical Review BMesoscale and Nanoscale Physicstext