Stanford University researchers have come up with ‘designer electrons’ – electrons whose properties can be controlled and fine-tuned. Leading the research is Hari Manoharan, associate professor at the Stanford Physics department. He reports that his group has created graphene-like electrons and then tweaked them!
Why is this important? Let Prof. Manoharan answer that question:
The behavior of electrons in materials is at the heart of essentially all of today’s technologies. We’re now able to tune the fundamental properties of electrons so they behave in ways rarely seen in ordinary materials.
Working with individual molecules
So, this is what they did. They placed carbon monoxide molecules on an atomically smooth copper substrate using a Scanning Tunneling Microscope (STM), which then created the potential mimicking that of the carbon atoms in graphene, forcing the electrons to behave like those of graphene. The peculiarity of graphene electrons is that, within graphene, they act as if they have no mass. They thus move at the maximum speed possible within the substrate. Manoharan calls this ‘molecular graphene’, built from scratch atom-by-atom.
Making electrons go crazy – at will
Manoharan’s group could then tweak the potential properties by changing the positions of the Carbon Monoxide molecules and then the electrons suddenly gained mass! More than that, they could make the electrons behave as if they were in an electric or magnetic field. Says Manoharan:
One of the wildest things we did was to make the electrons think they are in a huge magnetic field when, in fact, no real field had been applied
The team is now looking to synthesize more semiconductor substances and also replicate certain properties of graphene. The team promises that more ‘Dirac materials’ are on the way! We live in exciting times.
The work is featured in Nature and it appeared yesterday. Here is the link: http://www.nature.com/nature/journal/v483/n7389/full/nature10941.html
More info from Stanford news: http://news.stanford.edu/news/2012/march/molecules-designer-electrons-031412.html
Also, do watch the video below, where the group explains their work. You do NOT want to miss this.