SPIN SPLITTING EFFECT ON THE EFFECTIVE-MASS OF GAAS ALXGA1-XAS QUANTUM-WELLS/

The enhancement of the electronic effective mass in GaAs/AlxGa1-xAs qu antum wells is investigated within the framework of a 14-band k.p theo ry. In this theory, the hulk conduction band dispersion is expanded to fourth order in the wave vector, k, and the anisotropy and spin split ting effects are also included. The analytical expressions for the non -confinement and confinement-direction masses are reformulated to take into account the spin splitting effect. The dependence of the effecti ve mass with the quantum well width is also discussed for different co mpositions of the barrier material (AlxGa1-xAs). It results that the s pin splitting effect on the effective mass decrease with increasing wi dths of the GaAs/AlxGa1-xAs quantum wells. For values of the well widt h greater than 10 nm, a value close to the bulk GaAs is obtained. This behaviour is similar to that reported in the literature for GaAs/AlxG a1-xAs quantum wires. (C) 1998 Elsevier Science B.V. All rights reserv ed.