Hy drogenic impurity effects on refractiv e index changes and absorpti on coefficients of a cylindrical quantum wire with a convex botto m in magn etic field

Recent advances in crystal growth technique hel p us to fab ricate semi conductor nano-struct ures such as quantum wells, wires and dots. In particular semiconduct or quantum wires (QWs) have gained a great importance due to the p ossibility of tuning the size, shape , and numb er of bound electrons. T he two-dim ensional quantum confinement of electrons in these struct ures, leads to the formation of discrete energy levels an d the drastic changes o f the absorp tion spectra as well as many novel physical properties which had not been observ ed in the bulk materials [۱,۲]. So, the purpose of this pape r is to investigate the effects of external magne tic field, geometrical size, convexity paramete r and hydro genic donor impurity o n the linear, the third-o rder nonlinear and the total optical absorption coefficien ts and refr activeindex changes o f the syste m. To this end, energy eigenvalues and eigenfunctions of a hydrogenic impurity confine d in a cylindrical quant um wire ha ve been obtained, using the matrix diagonalization method. Also, by means of the compact-density matrix approac h the linear and nonlinear optical absorption c oefficients and refractive index ch anges have been calculated [۳].

کلیدواژه ها:

hydrogenic impurity ، magnetic field ، refra ctive index ، absorption coefficient