We report an intriguing transition from the quantum spin Hall phase to the spin Hall effect upon ... more We report an intriguing transition from the quantum spin Hall phase to the spin Hall effect upon segregation of thallium adatoms adsorbed onto a graphene surface. Landauer-Büttiker and Kubo-Greenwood simulations are used to access both edge and bulk transport physics in disordered thallium-functionalized graphene systems of realistic sizes. Our findings not only quantify the detrimental effects of adatom clustering in the formation of the topological state, but also provide evidence for the emergence of spin accumulation at opposite sample edges driven by spin-dependent scattering induced by thallium islands, which eventually results in a minimum bulk conductivity ∼4e^{2}/h, insensitive to localization effects.
We calculate the dynamical dielectric function of doped double-layer graphene (DLG), made of two ... more We calculate the dynamical dielectric function of doped double-layer graphene (DLG), made of two parallel graphene monolayers with carrier densities \(n_1, n_2\), respectively, and a separation interlayer of \(d\) at finite temperature. The results are used to find the dispersion of plasmon modes. We study the temperature effects on the DLG plasmon modes in the case of symmetric system \((n_1=n_2)\), asymmetric system \((n_1\neq n_2)\) and no free carriers in the second layer \((n_2=0)\). We show that the effect of temperature on the plasmon dispersion is significant and can not be ignored in investigating graphene properties.
We report an intriguing transition from the quantum spin Hall phase to the spin Hall effect upon ... more We report an intriguing transition from the quantum spin Hall phase to the spin Hall effect upon segregation of thallium adatoms adsorbed onto a graphene surface. Landauer-Büttiker and Kubo-Greenwood simulations are used to access both edge and bulk transport physics in disordered thallium-functionalized graphene systems of realistic sizes. Our findings not only quantify the detrimental effects of adatom clustering in the formation of the topological state, but also provide evidence for the emergence of spin accumulation at opposite sample edges driven by spin-dependent scattering induced by thallium islands, which eventually results in a minimum bulk conductivity ∼4e^{2}/h, insensitive to localization effects.
We calculate the dynamical dielectric function of doped double-layer graphene (DLG), made of two ... more We calculate the dynamical dielectric function of doped double-layer graphene (DLG), made of two parallel graphene monolayers with carrier densities \(n_1, n_2\), respectively, and a separation interlayer of \(d\) at finite temperature. The results are used to find the dispersion of plasmon modes. We study the temperature effects on the DLG plasmon modes in the case of symmetric system \((n_1=n_2)\), asymmetric system \((n_1\neq n_2)\) and no free carriers in the second layer \((n_2=0)\). We show that the effect of temperature on the plasmon dispersion is significant and can not be ignored in investigating graphene properties.
Uploads
Papers by Tuan Dinh Van