Produção Nacional
Observation of densely populated Tamm states in modulation-doped superlattices
2000; American Physical Society; Volume: 61; Issue: 20 Linguagem: Inglês
10.1103/physrevb.61.r13369
ISSN1095-3795
AutoresA. B. Henriques, L. K. Hanamoto, P. L. Souza, B. Yavich,
Tópico(s)Cold Atom Physics and Bose-Einstein Condensates
ResumoWe have observed densely populated surface-localized states (Tamm states) in doped lattice-matched ${\mathrm{I}\mathrm{n}\mathrm{P}/\mathrm{I}\mathrm{n}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$ superlattices. The formation of Tamm states is manifested in the Shubnikov--de Haas (SdH) spectra in tilted magnetic fields. Along with SdH oscillations due to quasi-three-dimensional (3D) carriers, which fill a superlattice miniband, SdH oscillations due to 2D carriers are seen. The 2D subband has an energy threshold greater than the superlattice miniband, and it is associated with surface-localized states. Cyclotron mass measurements and theoretical calculations of the electronic energy levels provide support for the interpretation. The role of the surface-localized states in the transport properties of the superlattice is also investigated.
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