Observation of Landau levels of Dirac fermions in graphite

By Guohong Li, E. Andrei. 2007

322 citations recorded by the source corpus.

The unique electronic behaviour of monolayer and bilayer graphene1,2 is a result of the unusual quantum-relativistic characteristics of the so-called ‘Dirac fermions’ (DFs) that carry charge in these materials. Although DFs in monolayer graphene move as if they were massless, and in bilayer graphene they do so with non-zero mass, all DFs show chirality, which gives rise to an unusual Landau level (LL) energy spectrum3,4,5,6,7,8,9,10,11 and the observation of an anomalous quantum Hall effect in both types of graphene4,5,8. Here we report low-temperature scanning tunnelling spectra of graphite subjected to a magnetic field of up to 12 T, which provide the first direct observations of the LLs that produce such behaviour. Unexpectedly, we find evidence for the coexistence of both massless and massive DFs in graphite, and confirm the quantum-relativistic nature of these quasiparticles through the appearance of a zero-energy LL.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/813cb52a74b3093b2e7ce5027436f8279a130d70

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In Atomic and Molecular Physics, and Optics

In Condensed Matter Physics

In Materials Chemistry

Citations in the corpus

Electronic properties of graphene in a strong magnetic field (2010, methodology): “12 With the help of the same technique, relativistic LLs had before been identified even in graphite (Li and Andrei, 2007).”
Colloquium: The transport properties of graphene: An introduction (2010, unknown): “5 for the definition of the mobility µ), as high as µ ∼ 1 × 107 cm2·V−1·s−1, have been indirectly measured by Landau level spectroscopy (Li and Andrei, 2007; Li et al., 2009) of graphene flakes on top of graphite (Neugebauer et al., 2009), raising the question of how perfect can graphene be…”
Electronic properties of graphene-based bilayer systems (2015, methodology): “Thus, the tight-binding Hamiltonian of the bilayer graphene can be written as a sum of the Hamiltonians of two single-layer graphene sheets and a term describing the electron hopping between these sheets.”
The electronic properties of graphene (2007, background): “18)(Novoselov et al., 2005a; Zhang et al., 2005), to infraredspe tros opy (Jiang et al., 2007a), and to s anning tun-neling spe tros opy (Li and Andrei, 2007) (STS) on agraphite surfa e.J.”