PhD thesis: Electronic and phonon properties of 2D layered materials
Roome, N. J., & Carey, J. D. (2014). Beyond graphene: stable elemental monolayers of silicene and germanene. ACS applied materials & interfaces, 6(10), 7743-7750.
Crystals and even small molecules vibrate by a very small amount very quickly and it has a noticeable effect on how well electricity moves through these materials. I have been looking into ways of calculating these effects and more importantly finding out if they are a good thing or a bad thing. Bad vibrations can get in the way. Just like when you’re squeezing through a crowded pub with a handful of drinks, people bumping into you can make you spill the drinks or just make it take a long time to get to your table. Whereas if the pub is full of nice people that notice you’re trying to get through, they can help and guide you through the crowd.
Application of Density Functional Theory (DFT)
Using computers to create virtual models of the world around us has been a valuable tool for all branches of society, from space missions to computer games, electronic engineering to architecture. Nowhere though is the difference in physics more profound than the difference between macro (>mm) and micro (<μm) physics; between classical and quantum mechanics. Application of theoretical quantum mechanics has been a difficult process, not least because of the complexity of the subject and high computational cost of many of the solutions. In the last decade or so one particular method has emerged as the most popular and applied solution due to the simplicity and efficiency, Density Functional Theory (DFT).
There are a variety of ways to apply the theory put the principle result is a total energy of the atomic system being modelled. The variation in methods emerges because the main variable is the way the density of electrons is spread across the system, for instance should only the local electrons or more long range effects be considered. From these humble components the DFT’s have been used to model crystals including metals and semiconductors, liquids and molecules. No chemistry or electronics department today would be complete without a basic understanding or integration of some flavour of DFT code.
The link between theory and experiment is a constant process of challenge and agreement that ultimately leads to a full and applicable understanding, density functional theory is just one versatile method of achieving this aim on the nanometre scale.
There are a variety of ways to apply the theory put the principle result is a total energy of the atomic system being modelled. The variation in methods emerges because the main variable is the way the density of electrons is spread across the system, for instance should only the local electrons or more long range effects be considered. From these humble components the DFT’s have been used to model crystals including metals and semiconductors, liquids and molecules. No chemistry or electronics department today would be complete without a basic understanding or integration of some flavour of DFT code.
The link between theory and experiment is a constant process of challenge and agreement that ultimately leads to a full and applicable understanding, density functional theory is just one versatile method of achieving this aim on the nanometre scale.