Nanoscale simulations from the semiconductor industry to the life science
Multi-scale and/or multi-disciplinary approach to process-product innovation
Nanotechnology: New Developments (T3-6)
Keywords: nanoscale, two-probe, life science, modelling
This talk discusses some of the challenges we are facing when electronic device are approaching the atomic scale and when the functional properties of molecules are structure dependent and cannot be explained from a macro level point of view. At this scale, we need to take into account the quantum nature of electrons.
In the first part we will give an introduction to the field of quantum transport, and describe how the quantum nature of electrons changes the properties of nanoscale devices and the challenges we face. The modelling of quantum transport is particularly difficult since the small scale requires that the quantum nature and the atomic details of the system are accurately described, while the size of the system
often comprises millions of atoms.
Some years ago we introduced the important notion of dividing a nanoscale device into an active device region and a passive electrode region[1]. In this way the simulation can often be limited to describing a few hundred atoms and it is possible to calculate the current-voltage characteristics of the device with ab initio electronic structure techniques[1]. This theoretical development has laid the foundation for the company Atomistix, in 2003.
In the second part of the talk we will tell the story behind Atomistix, the theory behind their software products, and some insight gained on using their software to model the electrical properties of nanoscale devices like carbon nanotubes[1], 1-D graphene sheets, molecular electronic devices[2], atomic wires[3], spin tronics
components or interfaces between different materials[4]. To conclude, the use of atomic-scale simulations to problems in chemistry, catalysis, and life science will be discussed together with a discussion of current and future challenges in the chemical industry.
References
1. Mads Brandbyge, Jose-Luis Mozos, Pablo Ordejon, Jeremy Taylor, and Kurt Stokbro, Density functional method for nonequilibrium electron transport, Phys. Rev. B. 65, 165401 (2002).
2. K. Stokbro, J. Taylor and M. Brandbyge, Do Aviram-Ratner diodes rectify?, J. of Amer. Chem. Soc. 125(13), 3674 (2003).
3. S. K. Nielsen, M. Brandbyge, K. Hansen, K. Stokbro, J. M. van Ruitenbeek, and F. Besenbacher, Current-Voltage Curves of Atomic-Sized Transition Metal Contacts: Why Au is Ohmic and Pt is Not, Phys. Rev. Lett. 89, 66804 (2002).
4. M. Stilling, K. Stokbro and K. Flensberg, Crystalline Magnetotunnel Junctions: Fe-MgO-Fe, Fe-FeOMgO-Fe and Fe-AuMgOAu-Fe, proceedings of Nanotech 2006, Boston May 2006.
Presented Tuesday 18, 11:00 to 11:20, in session Nanotechnology: New Developments (T3-6).
