Exciton Band Structure in Two-Dimensional Materials

Exciton Band Structure in Two-Dimensional Materials.

Low-dimensional materials differ from their bulk counterparts in many respects. In particular, the screening of the Coulomb interaction is strongly reduced, which can have important consequences such as the significant increase of exciton binding energies. In bulk materials the binding energy is used as an indicator in optical spectra to distinguish different kinds of excitons, but this is not ...

Exciton mapping at subwavelength scales in two-dimensional materials.

Spatially resolved electron-energy-loss spectroscopy (EELS) is performed at diffuse interfaces between MoS2 and MoSe2 single layers. With a monochromated electron source (20 meV) we successfully probe excitons near the interface by obtaining the low loss spectra at the nanometer scale. The exciton maps clearly show variations even with a 10 nm separation between measurements; consequently, the ...

Band structure calculation in two-dimensional Kerr-nonlinear photonic crystals

Using the finite-difference time-domain method, based on the numerical simulation of oscillating dipole radiation, we analyze band structures in two-dimensional Kerr-nonlinear photonic crystals. This method is more thorough at calculating band structures in two-dimensional Kerr-nonlinear photonic crystals than approaches proposed earlier. We find that the band structures calculated for both TE ...

Electron band structure in a two-dimensional periodic magnetic field.

In this paper we study the energy spectrum of a two dimensional electron gas (2DEG) in a two dimensional periodic magnetic field. Both a square magnetic lattice and a triangular one are considered. We consider the general case where the magnetic field in a cell can be of any shape. A general feature of the band structure is bandwidth oscillation as a function of the Landau index. A triangular m...

Photonic band structure of two-dimensional atomic lattices