materialsphysicsresearch news

New STM technique studies topological electronic properties

By 1st October 2019 No Comments

Researchers from France, the Netherlands and Spain have developed a new scanning tunneling microscope technique to study the topological electronic properties of materials and have imaged a topological singularity near a hydrogen atom grafted on a graphene surface. The work, published in Nature, shows how the techniques could be applied to other materials in the search for new topological electronic states.

topological STM

Top: 3D reconstruction of the raw scanning tunneling microscope image. On the right, an artistic representation of the scanning tunneling microscope tip used to record the image. The dome corresponds to the hydrogen atom. Some of the oscillations seen in the image result from the rearrangement of electrons around the hydrogen atom. Bottom: the corresponding signal selected from the original image and amplified. Additional wavefronts (dislocations) in electronic density, which are real space manifestation of graphene’s abstract singularity, can be seen. Courtesy: V Renard et al.

The French members of the team are from the Université Grenoble Alpes, the University of Bordeaux, the CEA and the CNRS. They are led by Vincent Renard.

Read the research paper: Measuring the Berry phase of graphene from wavefront dislocations in Friedel oscillations. Vincent Renard et al. Nature 10.1038/s41586-019-1613-5

Read the press release from the Universidad Autónoma de Madrid.