TITLE: Electron interaction driven modification of graphene’s band structure measured with the quantum twisting microscope
AUTHOR: Dr. Martin Lee Department of Applied Physics and Science Education Eindhoven University of Technology
WHEN: January, 29 - 12PM
WHERE: Salón de Actos, ICMM-CSIC
ABSTRACT: The band structure of a material greatly dictates its properties. It is therefore imperative that the band structure is understood before the properties of a material can be harnessed in useful devices. While leading experimental techniques such as angle-resolved-photo-emission-spectroscopy (ARPES) have been successful in measuring the band structures of large conventional
materials, they are less adequate for small devices at the level of exfoliated flakes. In recent years, a new revolutionary band structure spectroscopy tool named the quantum twisting microscope (QTM) has been invented where the in-situ twisting motion provides the momentum resolution. In this talk, I will give an overview of the QTM technique and its complementarity to ARPES. As an example of it’s experimental capability, I will show our recent work where we use the QTM to measure the renormalized band structure
of monolayer graphene. Graphene has a famously linear dispersion relation in the single particle limit, making it the archetypal Dirac semimetal with a constant Fermi velocity of ∼ 106 m/s. In clean samples, many-body corrections to the single particle band structure have been observed where the Fermi velocity diverges at the charge neutrality point. We show with our QTM that this effect persists to room temperatures.
