2007/02/28 by Tigran Sedrakyan, T. A. Sedrakyan, E. G. Mishchenko +2 · 1 citation
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.mes-hall #hep-th
paper · pdf · doi:10.1103/physrevlett.99.206405
published as Phys.Rev.Lett.99:206405,2007 · 4+ pages, 3 figures
openalex publication_date 2007/11/16 · arxiv created 2007/11/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We show that smooth variations, \ensuremathδn(r), of the local electron concentration in a clean 2D electron gas give rise to a zero-bias anomaly in the tunnel density of states, \ensuremathν(\ensuremathω), even in the absence of scatterers, and thus, without the Friedel oscillations. The energy width, \ensuremathω0, of the anomaly scales with the magnitude, \ensuremathδn, and characteristic spatial extent, D, of the fluctuations as (\ensuremathδn/D)2/3, while the relative magnitude \ensuremathδ\ensuremathν/\ensuremathν scales as (\ensuremathδn/D). With increasing \ensuremathω, the averaged \ensuremathδ\ensuremathν oscillates with \ensuremathω. We demonstrate that the origin of the anomaly is a weak curving of the classical electron trajectories due to the smooth inhomogeneity of the gas. This curving suppresses the corrections to the electron self-energy which come from the virtual processes involving two electron-hole pairs.