FUNDAMENTAL PROPERTIES OF LOW DIMENSIONAL SYSTEMS AND QUANTUM MATERIALS

Research on low-dimensional systems such as graphene, 2D topological insulators or 1D nanowires is essential for the development of novel types of nanoscale devices that exploit a range of exotic electronic and magnetic effects. Placing two different 2D layers close enough (e.g. by intercalation) may transfer these properties between adjacent layers by virtual electron hopping. Exploring proximity effects (superconductivity, magnetism, strong spin-orbit coupling) in combinations of different atomically thin layers is, thus of the utmost interest.

We have demonstrated that a monolayer of Pb intercalated below graphene transfers a giant spin-orbit coupling to graphene by electron hopping between these layers, and it has been suggested theoretically that, in these circumstances, graphene may turn into a 2D topological insulator, i.e. a Quantum Spin Hall phase. Other types of quantum materials that develop totally new properties, such as topologically protected edge states, Majorana excitations and so on via proximity effects, are explored with the aid of local spectroscopic methods and ex-situ electrical measurements.

Senior co-workers: Dr. Andrew Norris, Dr. Fabián Calleja, Prof. A.L. Vázquez de Parga, Prof. F. Guinea

Key publications

• “Spatial variation of Giant Spin Orbit effect induces electron confinement in graphene on Pb islands” 
  • F. Calleja, H. Ochoa, M. Garnica, S. Barja, J.J. Navarro, A, Black, M. M. Otrokov, E. Chulkov, A, Arnau, A.L. Vázquez de Parga, F. Guinea, and R. Miranda 
  • Nature Physics 11, 43-47 (2015)