Quantum mechanics

Raman spectroscopy

Materials science

Graphene

Curse of dimensionality

Electronic structure

Phonon

Computer science

Physics

Nanotechnology

Carbon nanotube

Graphite

Mathematics

Optics

Condensed matter physics

Block (permutation group theory)

Geometry

Composite material

Fullerene

Machine learning

Physical Review Letters

Graphene is the two-dimensional building block for carbon allotropes of every other dimensionality. We show that its electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers. The D peak second order changes in shape, width, and position for an increasing number of layers, reflecting the change in the electron bands via a double resonant Raman process. The G peak slightly down-shifts. This allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area.

Raman Spectrum of Graphene and Graphene Layers