Electron scattering in two-dimensional semiconductors: Contrasting massive Dirac and Schrodinger behavior

Autor(es)

Meneses-Gustin, D. ; Ulloa, S. E. ; Lopez-Richard, V

• Tipo de documento: Artigo Científico
• Fonte: PHYSICAL REVIEW B; v. 98, n. 12, p. 7-pg., 2018-09-06.

Resumo

Electronic transport through a material depends on the response to local perturbations induced by defects or impurities in the material. The scattering processes can be described in terms of phase shifts and corresponding cross sections. The multiorbital nature of the spinor states in transition metal dichalcogenides would naturally suggest the consideration of a massive Dirac equation to describe the problem, while the parabolic dispersion of its conduction and valence bands would invite a simpler Schrodinger equation description. Here, we contrast the scattering of massive Dirac particles and Schrodinger electrons, in order to assess different asymptotic regimes (low and high Fermi energy) for each one of the electronic models and describe their regime of validity or transition. At low energies, where the dispersion is approximately parabolic, the scattering processes are dominated by low angular momentum channels, which results in nearly isotropic scattering amplitudes. On the other hand, the differential cross section at high Fermi energies exhibits clear signatures of the linear band dispersion, as the partial phase shifts approach a nonzero value. We analyze the electronic dynamics by presenting differential cross sections for both attractive and repulsive scattering centers. The dissimilar behavior between Dirac and Schrodinger carriers points to the limits and conditions over which different descriptions are required for the reliable treatment of scattering processes in these materials. (AU)

• Processo FAPESP: 14/02112-3 - Fenômenos ópticos e de transporte em nano-dispositivos
• Beneficiário: Victor Lopez Richard
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/24253-5 - Propriedades eletrônicas e ópticas de nano-estruturas quase-bidimensionais e sistemas esfoliáveis
• Beneficiário: Diana Mercedes Meneses Gustin
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 16/02065-0 - Transporte de portadores em filmes finos exfoliados de di-calcogenetos ativados por luz
• Beneficiário: Diana Mercedes Meneses Gustin
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado