Spin Excitations of the Spin-Polarized Electron Gas in Semimagnetic Quantum Wells

B. Jusserand (1) , F. Perez (1) , D. R. Richards (2) , G. Karczewski (3) , T. Wojtowicz (3) , C. Testelin (4) , D. Wolverson (5) , J. J. Davies (5)

1 LPN - Laboratoire de photonique et de nanostructures
2 Dpt of Physics [London]
3 IFPAN - Institute of Physics [Warsaw]
4 GPS - Groupe de Physique des Solides
5 Department of Physics [Bath]

Collective and single-particle spin-flip excitations of a two-dimensional electron gas in a semimagnetic Cd1–xMnxTe quantum well are observed by resonant Raman scattering. Application of a magnetic field splits the spin subbands and a spin polarization is induced in the electron gas. Above 1 T the collective modes, which disperse with the in-plane wave vector, dominate the spectra. The local spin-density approximation provides a good description of our results and enables us to confirm that the energy of the low wave vector collective mode is given by the bare Zeeman energy.

Domaines: Physique [physics]

B. Jusserand, F. Perez, D. R. Richards, G. Karczewski, T. Wojtowicz, et al.. Spin Excitations of the Spin-Polarized Electron Gas in Semimagnetic Quantum Wells. Physical Review Letters, 2003, 91 (8), pp.086802. ⟨10.1103/PhysRevLett.91.086802⟩. ⟨hal-00002783⟩