The proposal for the FOM programme 'Topological Insulators', submitted by programme leader prof. dr. Mark Golden, has been selected along with four other national programmes for funding.

With this grant, Golden and colleagues from the UvA's Institute of Physics (Kareljan Schoutens, Jeroen Goedkoop, Anne de Visser and Yingkai Huang) will be able to extend and accelerate their research in this field. The programme consortium also contains research teams from Delft, Twente and Leiden.

A new spin on conductivity

Topological insulators are new materials in which the fundamental mathematics of topology can be found in the guise of conducting edge states. In this sense, they possess two faces: an insulating one - in the bulk of the material - and a metallic one, at the edges of the sample. Surface states are possible in other systems, too, but the TI's have raised such excitement as their conducting edge states are both topologically protected from back-scattering and 100% spin polarised, making them an attractive materials platform for a future low-power spintronic technology and even for use in topological quantum computing.

The figure illustrates how a topologically non-trivial entity (the Trefoil knot, right) is different from a topologically trivial loop. Only by cutting the rope - thereby creating a new surface (in yellow) - can one go from one form to the other. In a similar manner, the electronic bands in the bulk of a TI have a peculiar twist, and at the interface to a regular, topologically trivial insulator (or vacuum) the knot must be cut and conducting edge states, are the consequence.

This field is seen by many as currently the most exciting in physics, and has sparked an enormous research effort, worldwide. FOM has now granted 2.7M€ to a research consortium led by prof. dr. Mark S. Golden of the Van der Waals-Zeeman Institute of the UvA's IoP to tackle this global hot topic. The programme brings together six research teams from four universities with the global aims to create, investigate and ultimately control topological edge/surface states in 2D/3D topological insulators.

Programme leader Mark Golden: "We are very excited by both the physics and prospects offered by 2D and 3D topological insulators. The FOM programme will enable us to combine experiment and theoretical expertise to understand and develop systems in which the topological electronic states dominate the transport properties. We hope to be among the very first to realise some of the beautiful and far-reaching theoretical predictions in this field."

See also

• FOM website