quantum corral (rus. "квантовый загон") — nano-object composed of adsorbate atoms arranged in a two-dimensional shape (circle, ellipse, square, triangle, etc.) on an atomically clean single-crystal metallic surface by manipulating a scanning tunnelling microscope (STM).

Description

In 1993 D. Eigler and his collaborators created a so-called "quantum corral" by placing 48 iron atoms in a circle on a copper surface and thus demonstrated a shining example of forming nano-objects through the manipulation of individual atoms with the use of scanning tunnelling microscopy (STM). A quantum corral acts as a two-dimensional cylindrical quantum well confining surface state electrons. Circular waves observed inside the corral in the STM image are standing waves of electron density, whose existence is predicted by Schrodinger's equation for those boundary conditions. The possibility of building quantum corrals of various shapes (triangular, rectangular, hexagonal, etc.) was shown. Using an elliptical ring of cobalt atoms on a copper surface, the researchers demonstrated the effect of "quantum mirage": when a cobalt atom was placed at one focus of the ellipse, a mirage of the atom appeared in the STM image at the other focus. Moreover, the electronic properties of the two-dimensional electron gas surrounding both foci were similar, even though the cobalt atom was only present at one focus.

Illustrations

A seria of STM images showing formation of a
A seria of STM images showing formation of a "quantum coral" from 48 Fe atoms adsorbed on the surface of Cu(111).

Authors

  • Zotov Andrey V.
  • Saranin Alexander A.

Sources

  1. Crommie M. F., Lutz C. P., Eigler D.M. Confinement of electrons to quantum corrals on a metal surface // Science. 1993. V. 262. P. 218–220.
  2. Crommie M. F., Lutz C. P., Eigler D.M. Imaging standing waves in a two-dimensional electron gas // Nature. 1993. V. 363. P. 524–527.
  3. STM Image Gallery // IBM, 1995. —www.almaden.ibm.com/vis/stm/corral.html (reference date: 12.12.2011).

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