Numerical study of bound states for point charges shielded by the response of a homogeneous two-dimensional electron gas

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Journal Title
Journal ISSN
Volume Title
School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2006
Major/Subject
Mcode
Degree programme
Language
en
Pages
115411/1-5
Series
Physical Review B, Volume 74, Issue 11
Abstract
We study numerically the existence and character of bound states for positive and negative point charges shielded by the response of a two-dimensional homogeneous electron gas. The problem is related to many physical situations and has recently arisen in experiments on impurities on metal surfaces with Shockley surface states. Mathematical theorems ascertain a bound state for two-dimensional circularly symmetric potentials V(r) with ∫∞0drrV(r)⩽0. We find that a shielded potential with ∫∞0drrV(r)>0 may also sustain a bound state. Moreover, on the same footing we study the electron-electron interactions in the two-dimensional electron gas, finding a bound state with an energy minimum for a certain electron gas density.
Description
Keywords
two-dimensional electron gas, screening, impurity potential, electron-electron interaction
Other note
Citation
Nagy, I. & Puska, Martti J. & Zabala, N. 2006. Numerical study of bound states for point charges shielded by the response of a homogeneous two-dimensional electron gas. Physical Review B. Volume 74, Issue 11. 115411/1-5. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.74.115411.