Development of a Rapid Graphene Simulation Tool using the Tight-Binding Method
| Speaker | Michael Tickell |
| Venue | P/T/111 |
| Time | 4pm on 20th March 2017 |
The tight-binding method has recently had a lot of success in simulating crystal structures. By using a tight-binding Hamiltonian to solve the Schrodinger equation and a unit cell approximation it is possible to build a 2D matrix which we solve to find the energy of a system for any given wavenumber.
The major advantage of this approach is its speed when modelling large systems and we have applied this to armchair graphene nanoribbons. We then continued to adjust parameters of the system to simulate different conditions such as changing the ribbon width, edge hydrogen passivation, applied uniaxial strain, and notch defects.
We developed this model by comparing results to those obtained in DFT and from there have continued with our own work including notable success from plotting the band gap as a function of the width and depth of a notch defect producing results which imply quantum confinement.
Bibliography
- "Generalized Tight-binding Transport Model for Graphene Nanoribbon-based Systems", Y. Hancock, A. Uppstu, K. Saloriutta, A. Harju and M.J. Puska, Phys. Rev. B 81(24) 245402 (2010)
- "Energy gaps in graphene nanoribbons", W. Son, M. L. Cohen and S. G. Louie, Phys. Rev. Lett. 97 216803 (2006)