RELATIONSHIP BETWEEN NONPARABOLICITY AND CONFINEMENT ENERGIES IN IN0.53GA0.47AS INP QUANTUM WIRES/

The magnetic-field effects on the electronic structure in lattice-matc hed InxGa1-xAs/InP quantum wires have been studied by low-temperature magnetophotoluminescence spectroscopy in magnetic fields up to 28 T. H igh cw Ar+-ion laser excitation is used in the experiments. The photoi nduced carrier density is high enough to populate several subbands, wh ich thereby become observable in the luminescence spectra. The subband structure in the wires is gradually resolved by the magnetic field, a s the magnetic field modifies the density of states and reduces the ef fects of the inhomogeneous linewidth broadening. By following how the one-dimensional subbands in the 350-Angstrom-wide wires merge into Lan dau levels we deduce an effective electron mass that is considerably l arger than the electron effective mass near the band edge in bulk In0. 53Ga0.47As. The enhancement of the electron effective mass in the quan tum wires is due to the strong quantum confinement effect in the wires and the nonparabolicity in the conduction-band dispersion in bulk In0 .53Ga0.47As. Furthermore, for the narrowest wires (150 Angstrom wide) we observe a dear subband structure in the zero-field spectra. The mag netic-field effect on the subband structure is very small, even at mag netic fields as high as 28 T, due to the strong lateral confinement in the wires. A theoretical calculation including band coupling and nonp arabolicity in both the conduction and the valence band is performed t o estimate the subband energy positions in the zero-field spectra.