The tunability of physical properties by application of an external electric field has created great excitation, mainly related to the development of new field effect transistors (FETs). The use of the field-effect approach to materials other than semiconductors brings many interesting opportunities in basic science and for the design of new electronic devices.
This recent line of research is very appealing for electronic structure methods based in first principles, because a quantum mechanical description at the atomic level is required to understand the physical processes involved. The problem of a periodic crystal in a finite macroscopic electric field is a challenge from a fundamental point of view.
The difficulties come from the unbounded nature of the quantum-mechanical position operator, and the fact that in a macroscopic field the electronic wave-functions are no longer of the Bloch form because the potential is "non-periodic". Only recently have these fundamental problems been understood, and a few "abinitio" implementations of the algorithms required for studying electric fields in materials are now available for studying relatively simple systems (few atoms). This is enough for basic research, but not for the application of these methods to realistic nano-devices.
Computer simulations of materials are a powerful scientific tool in physics, material science, surface science, chemistry, biology, or earth sciences. Nanotechnology will require simulations of systems with hundreds of atoms under the effect of electric fields. This research project proposes the implementation of tools to perform these calculations.
Our main interest is the use of these tools for the study of the new electronic devices whose physical properties can be tuned by electric fields. The dielectric properties of SrTiO3/BaTiO3 superlattices, the electro-optical properties of semiconductor nanostructures and the electromechanical properties of nanotubes will be investigated.
Call for proposal
See other projects for this call