Study of intersubband transition energy in a core-shell cylindrical quantum wire in comparison with square nanowire using finite difference technique

Energy eigenvalues for lowest three states and corresponding intersubband transition energies along with density of states of a core-shell cylindrical quantum wire is numerically computed using finite-difference technique (FDQ). Time-independent Schrödinger´s equation is solved with appropriate boundary conditions, arises due to geometrical nature and effective mass mismatch at heterojunction. The wire is made of lower bandgap GaAs material surrounded by wider bandgap Al_xGa_1-xAs, and conduction band discontinuity is considered for simulation purpose for near accurate evaluation. The eigenvalues and the density of states are plotted as function of wire dimension and strength of wire. Results are compared with those obtained using square coreshell quantum wire, and interesting features are obtained from relative energy values. It is observed that cylindrical nanowire has better optical tuning features than square quantum wire.