Nobel prize topic: GSI scientists hunt for exotic quantum materials
The search for exotic quantum states – the Nobel Prize in physics is awarded to three British scientists for their pioneering contribution to this field of research. Also at the GSI Helmholtzzentrum für Schwerionenforschung active research is conducted in this topic.
The Nobel laureates David Thouless, Duncan Haldane and Michael Kosterlitz accept their award for their theoretical work on the description and prediction of exotic states of matter. Since the formulation of this model, generations of scientists have joined the successful search for these new exotic materials. The Materials Research department at GSI is joining the quest. The scientists use the ion beam provided by the linear accelerator at GSI, called UNILAC to synthesize and investigate these materials on a very small scale.
The topic of investigation focuses on the so called Topological Insulators. These materials are actually insulating, but exhibit electrical conducting on their surface. Since this ability to conduct only occurs within a very thin layer, which is one atom thick, the scattering of electrons is reduced resulting in very low resistive electrical transport. Additionally, the spin of the electrons, amounting to two values - “up” or “down” -, is coupled to the direction of electron motion. Finding a way of manipulating the spin opens new possibilities in information transfer technology.
In the framework of her PhD thesis in the Materials Research department at GSI, Janina Krieg synthesizes nanowires of the Topological Insulator material bismuth-telluride which are as small as 1/10000 of the thickness of a hair. By fabricating tiny electrical contacts, an electrical potential can be applied to a single nanowire. Adding a very strong magnetic field (250000 times that of the earth), the exotic surface states are investigated. This knowledge is a further step on the route towards energy efficient electronics and fast-computing quantum computer applications.