Observation of Van Hove singularities in twisted graphene layers

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Guohong H Li (Author) Other; Luican, A (Author) Other; Lopes dos Santos, JMBL (Author) FCUP; Castro Neto, AH (Author) Other; Reina, A (Author) Other; Kong, J (Author) Other; Andrei, EY (Author) Other

Journal

Title: Nature Physics

Vol. 6 No. 2

Pages: 109-113

ISSN: 1745-2473

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 794 Citations

Scopus - 820 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-003-9HF

DOI: 10.1038/nphys1463

Abstract (EN): Electronic instabilities at the crossing of the Fermi energy with a Van Hove singularity(1) in the density of states often lead to new phases of matter such as superconductivity(2,3), magnetism(4) or density waves(5). However, in most materials this condition is difficult to control. In the case of single-layer graphene, the singularity is too far from the Fermi energy(6) and hence difficult to reach with standard doping and gating techniques(7). Here we report the observation of low-energy Van Hove singularities in twisted graphene layers seen as two pronounced peaks in the density of states measured by scanning tunnelling spectroscopy. We demonstrate that a rotation between stacked graphene layers can generate Van Hove singularities, which can be brought arbitrarily close to the Fermi energy by varying the angle of rotation. This opens intriguing prospects for Van Hove singularity engineering of electronic phases.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5