2009/10/31 by Akira Endo, Yasuhiro Iye
Chemistry · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Quantum and electron transport phenomena #Topological Materials and Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1143/jpsj.79.034701
published as J. Phys. Soc. Jpn. 79 (2010) 034701 · 7 pages, 6 figures, minor revision
arxiv created 2009/12/18 · openalex publication_date 2010/02/25 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/28
We have measured activation gaps for odd-integer quantum Hall states in a unidirectional lateral superlattice (ULSL) -- a two-dimensional electron gas (2DEG) subjected to a unidirectional periodic modulation of the electrostatic potential. By comparing the activation gaps with those simultaneously measured in the adjacent section of the same 2DEG sample without modulation, we find that the gaps are reduced in the ULSL by an amount corresponding to the width acquired by the Landau levels through the introduction of the modulation. The decrement of the activation gap varies with the magnetic field following the variation of the Landau bandwidth due to the commensurability effect. Notably, the decrement vanishes at the flat band conditions.