Measuring the Zeeman energy and the spin polarization of a 2DEG in quantum wells

Cynthia Aku-Leh (1) , Florent Perez (1) , Bernard Jusserand (1) , David Richards , Grzegorz Karczewski (2)

1 INSP - Institut des Nanosciences de Paris
2 Institute of Physics

We compare Raman scattering (RS) and photoluminescence (PL) measurements on a spin-polarized two-dimensional electron gases (2DEG) in Cd1-xMnx Te quantum wells in an applied magnetic field. RS spectra, for zero wave vector, show the collective spin-flip excitation corresponding to the Zeeman energy Z and the single electron spin-flip energy Z*. The Voigt magneto-PL spectra show conduction band splitting, which matches Z rather than Z*, indicating that the PL spectra are influenced by collective effects. Differences in the spin polarization values for large electron densities are also observed and attributed to the renormalization of mass due to Coulomb interactions. (c) 2007 Elsevier B.V. All rights reserved.

Mots clés: spin polarized two-dimensional electron gas; Raman scattering; dilute magnetic semiconductors; photoluminescence

Domaines: Matière Condensée [cond-mat]

Cynthia Aku-Leh, Florent Perez, Bernard Jusserand, David Richards, Grzegorz Karczewski. Measuring the Zeeman energy and the spin polarization of a 2DEG in quantum wells. Physica E: Low-dimensional Systems and Nanostructures, 2008, 40 (6), pp.1865-1866. ⟨10.1016/j.physe.2007.08.043⟩. ⟨hal-01287870⟩