Browsing NTNU Open by Author "Portnoi, M.E."

Now showing items 1-7 of 7

    • Electro-absorption of silicene and bilayer graphene quantum dots 

      Abdelsalam, H.; Talaat, M.H.; Lukyanchuk, I.; Portnoi, M.E.; Saroka, Vasil (Journal article; Peer reviewed, 2016)
      We study numerically the optical properties of low-buckled silicene and AB-stacked bilayer graphene quantum dots subjected to an external electric field, which is normal to their surface. Within the tight-binding model, ...

    • Electro-optical properties of phoshorene quantum dots 

      Saroka, Vasil; Lukyanchuk, I.; Portnoi, M.E.; Abdelsalam, H. (Journal article; Peer reviewed, 2017)
      We study electronic and optical properties of single layer phosphorene quantum dots with various shapes, sizes, and edge types (including disordered edges) subjected to an external electric field normal to the structure ...

    • Hidden correlation between absorption peaks in achiral carbon nanotubes and nanoribbons 

      Saroka, Vasil; Pushkarchuk, A.L.; Kuten, S.A.; Portnoi, M.E. (Journal article; Peer reviewed, 2018)
      In this paper we study the effect of absorption peak correlation in finite length carbonnanotubes and graphene nanoribbons. It is shown, in the orthogonalp-orbital tight-binding modelwith the nearest neighbor approximation, ...

    • Interband transitions in narrow-gap carbon nanotubes and graphene nanoribbons 

      Hartmann, R.R.; Saroka, Vasil; Portnoi, M.E. (Journal article; Peer reviewed, 2019)
      We use the robust nearest-neighbor tight-binding approximation to study the same footing interband dipole transitions in narrow-bandgap carbon nanotubes (CNTs) and graphene nanoribbons (GNRs). It is demonstrated that ...

    • Multilayer phosphorene quantum dots in an electric field: Energy levels and optical absorption 

      Abdelsalam, H.; Saroka, Vasil; Lukyanchuk, I.; Portnoi, M.E. (Journal article; Peer reviewed, 2018)
      Triangular and hexagonal multilayer phosphorene quantum dots with armchair and zigzag terminations are investigated with the orthogonal tight-binding model. The effect of increasing the number of layers is revealed. The ...

    • Optical selection rules of zigzag graphene nanoribbons 

      Saroka, Vasil; Shuba, M.V.; Portnoi, M.E. (Journal article; Peer reviewed, 2017)
      We present an analytical tight-binding theory of the optical properties of graphene nanoribbons with zigzag edges. Applying the transfer matrix technique to the nearest-neighbor tight-binding Hamiltonian, we derive analytical ...

    • Strong light-matter coupling in carbon nanotubes as a route to exciton brightening 

      Shahnazaryan, V. A.; Saroka, Vasil; Shelykh, I. A.; Barnes, W. l.; Portnoi, M.E. (Journal article; Peer reviewed, 2019)
      We show that strong light–matter coupling can be used to overcome a long-standing problem that has prevented efficient optical emission from carbon nanotubes. The luminescence from the nominally bright exciton state of ...