@InProceedings{ChittaPODMPRUA:2006:InQuHa,
               author = "Chitta, V. A. and Peres, M. L. and Oliveira J{\'u}nior, N. F. and 
                         Desrat, W. and Maude, D. K. and Piot, B. A. and Rappl, Paulo 
                         Henrique de Oliveira and Ueta, Antonio Yukio and Abramof, 
                         Eduardo",
          affiliation = "Instituto de F{\'{\i}}sica, Universidade de S{\~a}o Paulo (USP) 
                         and Instituto de F{\'{\i}}sica, Universidade de S{\~a}o Paulo 
                         (USP) and Instituto de F{\'{\i}}sica, Universidade de S{\~a}o 
                         Paulo (USP) and {Grenoble High Magnetic Field Laboratory} and 
                         {Grenoble High Magnetic Field Laboratory} and {Grenoble High 
                         Magnetic Field Laboratory} and Instituto Nacional de Pesquisas 
                         Espaciais, Laborat{\'o}rio Associado de Sensores e Materiais 
                         (INPE.LAS) and Instituto Nacional de Pesquisas Espaciais, 
                         Laborat{\'o}rio Associado de Sensores e Materiais (INPE.LAS) and 
                         Instituto Nacional de Pesquisas Espaciais, Laborat{\'o}rio 
                         Associado de Sensores e Materiais (INPE.LAS)",
                title = "Integer quantum Hall effect in a multivalley PbTe quantum well",
            booktitle = "Resumos...",
                 year = "2006",
         organization = "Encontro Nacional de F{\'{\i}}sica da Mat{\'e}ria Condensada, 
                         29.",
             abstract = "PbTe is a IV-VI semiconductor material which is characterized by a 
                         narrow energy gap, large values of dieletric constant and g 
                         factor, a small effective mass and a Fermi surface composed by 
                         four equivalent strongly anisotropic ellipsoids of revolution with 
                         their main axis along the (111) directions. The large dielectric 
                         constant is responsible by an effective screening of charged 
                         impurities, defects, and dislocations, which added to a small 
                         effective mass results in a high electron mobility. These make 
                         PbTe quantum wells a model system for studying the quantum Hall 
                         effect in the absence of electron-electron interactions. We have 
                         measured the integer quantum Hall effect in a 10nm 
                         PbEuTe/PbTe/PbEuTe quantum well grown by molecular beam epitaxy on 
                         a (111) BaF2. The inverse Hall resistance (1/Rxy) and longitudinal 
                         resistance (Rxx) show clearly de¯ned signature of the integer 
                         quantum Hall effect with well de¯ned plateau in Rxy(B) and a zero 
                         resistance state in Rxx(B). The measured electron density from the 
                         inverse period of the Shubnikov de Haas oscillations is ns = 2:23 
                         £ 1012 cm¡2 compared with ns = 2:28 £ 1012 cm¡2 measured from the 
                         low ¯eld Hall resistance slope. In contrast to previous work, our 
                         PbTe quantum well sample shows no sign of parallel conduction. For 
                         a heterostructure grown along the [111] crystallographic 
                         direction, the fourfold degeneracy of the Fermi surface is lifted 
                         due to the con¯nement. The large anisotropy and multivalley nature 
                         give rise to a complex density of states, leading to a nontrivial 
                         behavior of the electronic transport as a function of the magnetic 
                         ¯eld. Due to the occupation of a singly degenerate longitudinal 
                         valley and the three fold degenerate oblique valleys, the Hall 
                         resistance is quantized for an unconventional sequence of ¯lling 
                         factors. As the magnetic ¯eld is swept the quantized Hall 
                         conductance can change by 1, 3 or 4 e2=h.",
  conference-location = "S{\~a}o Louren{\c{c}}o, MG.",
      conference-year = "2006-05--09",
             language = "pt",
           targetfile = "chitta_integer.pdf",
        urlaccessdate = "20 maio 2024"
}