In this paper

we study the quantum confinement effect and effective Coulomb interaction in doped semiconductor quantum wire based on a two-band model.Single particle wave-function of carriers in T-shaped GaAs quantum wire can be obtained by finite-element solution of Schr dinger equation with complex boundary condition.The effective Coulomb interactions are calculated by using envelop function approximation.Due to their heavier mass

the quantum confinement effect of heavy holes is stronger than the electrons.The effective h-h Coulomb interaction increases with the intensity of electric field

while e-e Coulomb interaction decreases with increasing intensity of electric field.The e-h Coulomb interaction shows complicated dependency on electric field

which indicates competition of localization and delocalization characters in electron and hole.