title: Determination of exciton reduced mass and gyromagnetic factor of wurtzite (InGa)As nanowires by photoluminescence spectroscopy under high magnetic fields.
abstract: Semiconductor nanowires (NWs) have the prospect of being employed as basic units for nanoscale devices and circuits. However, the impact of their one-dimensional geometry and peculiar crystal phase on transport and spin characteristics remains largely unknown. We determine the exciton reduced mass and gyromagnetic factor of (InGa)As NWs in the wurtzite phase by photoluminescence (PL) spectroscopy under very high magnetic fields. For B perpendicular to the NW ĉ axis, the exciton reduced mass is 10% greater than that expected for the zincblende phase and no field-induced circular polarization of PL is observed. For B parallel to ĉ, an exciton reduced mass 35% greater than that of the zincblende phase is derived. Moreover, a circular dichroism of 70% is found at 28 T. Finally, an analysis of the PL line shape points at two Zeeman split levels, whose separation corresponds to an exciton gyromagnetic factor |g(e) - g(h,∥)| = 5.8. These results provide a quantitative estimate of the basic electronic and spin properties of NWs and may guide a theoretical analysis of the band structure of these fascinating nanostructures.
authors.affiliation: Dipartimento di Fisica and CNISM, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: De Luca
authors.forename: Antonio
authors.initials: A
authors.lastname: Polimeni
authors.forename: Mario
authors.initials: M
authors.lastname: Capizzi
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Meaney
authors.forename: Peter C M
authors.initials: PC
authors.lastname: Christianen
authors.forename: Jan Kees
authors.initials: JK
authors.lastname: Maan
authors.forename: Francesco
authors.initials: F
authors.lastname: Mura
authors.forename: Silvia
authors.initials: S
authors.lastname: Rubini
authors.forename: Faustino
authors.initials: F
authors.lastname: Martelli