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Veni Grant for Leiden Physicist Johannes Jobst

Johannes Jobst - researcher at the Leiden Institute of Physics (LION) – has been awarded a Veni grant from the Netherlands Organisation for Scientific Research (NWO). Veni grants are handed out to very talented researchers who have recently obtained a PhD. Jobst receives the maximum amount of 250,000 euro and will use the money to study how electric switching affects free-flying electrons in graphene transistors.

Graphene is made up of just a single layer of carbon atoms, and has shown great promise for a wide range of applications since its discovery in 2004. The material even earned a Physics Nobel Prize in 2010, awarded to Kostya Novoselov and Dutchman Andre Geim. One of the amazing properties of graphene is its incredible conductivity; electrons travel large distances without changing direction. Compared to conventional semiconductors, that are commonly used in electric devices, this promises great performance improvements.

The key to improving computers is the computer chip – a series of many tiny electric switches, or transistors. Simply put: the faster transistors switch, the faster computers are. And more of them means a more powerful computer. We cannot make traditional silicon transistors any faster, and for the past years the main effort has been put into making them smaller in order to squeeze more on a chip. However, we’ll soon reach a minimum size beyond which this transistor faces limitations, putting technology progress to a halt.

The solution may lie in graphene transistors. They switch faster than silicon and therefore increase computers speeds. ‘In theory they are a thousand times faster,’ says Jobst. ‘So instead of three gigahertz computers, we'd have clock rates of three terahertz. And because electrons fly freely in graphene without scattering, they produce much less waste heat, meaning a lot less power consumption.’

But computers should also work in practise, not just in theory. What will happen when we actually use graphene in electric switches? How will the electric field, used to switch such transistors, affect the free-flying electrons? By using a novel technique, based on low-energy electron microscopy (LEEM), Jobst is going to find out what happens. The Veni grant enables him to perform his research at LION and Columbia University, New York for three more years as senior postdoctoral researcher.

single layer to triplelayer graphene
The novel microscopy technique that Jobst will use in his Veni research allows him to image where electrons scatter in graphene. In this example, the transition from single layer to triplelayer graphene (marked by arrows) can be identified as a major source of scattering.

Erik Arends
Physics Outreach Officer
arends [at]
+31 (0)71 527 5471
Twitter: @LeidenPhysics

Publ. 17-07-2015 14:04
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