Single Particle and Collective Spin Excitations in Semimagnetic Quantum Wells |
| F. Perez, B. Jusserand
CNRS/LPN, Route de Nozay, 91460 Marcoussis, France D. Richards Dept. of Physics, Kings College London, Strand, London WC2R 2LS, UK and G. Karczewski Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland |
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| Received: 10 06 2004 |
| 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 some critical field, a collective spin-flip mode, which disperses with in-plane wave vector, dominates the spectra. The energy of this mode is given by the bare Zeeman energy at vanishing wave vector as predicted by Larmor's theorem and its in-plane dispersion is well described by a model of the interacting polarizability of a spin polarized electron gas when both exchange and correlation are taken into account. |
| DOI: 10.12693/APhysPolA.106.311 PACS numbers: 72.25.Dc, 73.21.-b, 75.70.-i, 78.30.-j |