## vaex03.in : Gated Ultra-Thin Body Structure

Requires: Victory Atomistic

Minimum Versions: Victory Atomistic 1.0.1.R

This example demonstrates the capability to calculate electronic bandstructures, potential and charge distribution in gated ultra-thin body structure[1].

The Material section part contains the crystal structures with name "MoS2". The detalied info resides in the all.mat file containing critical dimension for the crystal structure, effective mass or dielectric constants. The hamiltonian file is pointed to by option created by wannier90 and post-processed for each atom which have the same orbital number. The ** readin_atom_xyz_file** contains the xyz coordinates of the unit cell with their atomic names indexed if duplicated, e.g. Mo1, Mo@. The ** number_of_orbitals** specifies the orbital numbers for each atom in the wannier process.

The stucture is altogether the intersection of the atomic domain and the Region specified by it's coordinates. In the Domain section, a pseudomorphic domain is created by repetition of a single unit cell with desired repeated number of unit cells. The device is periodic in the xy directions while seperated into 3 regions in the z direction. Region 1 decides the MoS2 layer number. Region 2 decides the oxide thickness. Region 3 decides the air thickness.

The poisson equation is solved with electron and holes density calculated from EK_e and EK_hi, respectively. The differential equation is solved with finite element method on a mesh provided by the {Bold} continuum solver with mesh tunable by options {Bold} dx, {Bold} dy, {Bold} dz. The nonlinear equation is iterated with numerical options and convergence criterial specified in the {Bold} poisson_device solver. Schroedinger solves the eigenvalue calculation for the hamiltonian with the Bloch phase due to periodicity. The {Bold} EK1 and {Bold} EK2 solvers calculate along specific k path (high symmetry point) designated by {Bold} k_points. EK1 solves with zero potential while EK2 is solved self-consistently with the potential from the {Bold} poisson_device solver.

Publication: [1] K. C. Wang, T. K. Stanev, D. Valencia, J. Charles, A. Henning, V. K. Sangwan, A. Lahiri, D. Mejia, P. Sarangapani, M. Povolotskyi, A. Afzalian, J. Maassen, G. Klimeck, M. C. Hersam, L. J. Lauhon, N. P. Stern, and T. Kubis, "Control of interlayer physics in 2H transition metal dichalcogenides," J. Appl. Phys., vol. 122, no. 22, 2017.

Visualization: 1. vtk structure output consists of the device structure. {Bold} Use Paraview to visualize these structure files (.vtk extension).

2. band structure data files and IV data files: Files with ".dat" extension. {Bold} Use a graph plotter such as Matlab, Python plotter, or Origin to visualize the data files.

To load and run this example, select the ** Load** button in DeckBuild > Examples. This will copy the input file and any support files to your current working directory. Select the ** Run** button in DeckBuild to execute the example.