2011/05/31 by Cheol-Hwan Park, Nicola Marzari · 1 citation
Chemistry · Materials Science · Physics and Astronomy · #Berry connection and curvature #Bilayer #Bilayer graphene #Chemistry #Condensed matter physics #Electron #Geometric phase #Graphene #Graphene research and applications #Phase (matter) #Physics #Quantum Hall effect #Quantum and electron transport phenomena #Quantum mechanics #Topological Materials and Phenomena #Wave function #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.84.205440
published as Phys. Rev. B 84, 205440 (2011) · 6 pages, 3 figures, published version
arxiv created 2011/11/18 · openalex publication_date 2011/11/18 · arxiv updated 2011/11/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Ever since the novel quantum Hall effect in bilayer graphene was discovered, and explained by a Berry phase of 2\ensuremathπ [K. S. Novoselov et al., Nat. Phys. 2, 177 (2006)], it has been widely accepted that the low-energy electronic wave function in this system is described by a nontrivial Berry phase of 2\ensuremathπ, different from the zero phase of a conventional two-dimensional electron gas. Here, we show that (i) the relevant Berry phase for bilayer graphene is not different from that for a conventional two-dimensional electron gas (as expected, given that Berry phase is only meaningful modulo 2\ensuremathπ), and (ii) what is actually observed in the quantum Hall measurements is not the absolute value of the Berry phase but the pseudospin winding number.