Atomic wires and their electronic properties

Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures

Volumn 15, Issue 4, 1997, Pages 1019-1026

  Yamada, Toshishige ^a  

^a STANFORD UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

BAND STRUCTURE; ELECTRODES; ELECTRONIC PROPERTIES; FERMI LEVEL; LATTICE CONSTANTS; MAGNESIUM; SILICON;

ATOMIC WIRES; COULOMB INTERACTION;

ELECTRIC WIRE;

EID: 0031185934     PISSN: 10711023     EISSN: None     Source Type: Journal    
DOI: 10.1116/1.589386     Document Type: Article

References (48)

1. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
2. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
3. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
4. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
5. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
6. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
7. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
8. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
9. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
10. For example: D. M. Eigler and E. K. Schweizer, Nature (London) 344, 524 (1990); J. A. Stroscio and D. M. Eigler, Science 254, 1319 (1991); I.-W. Lyo and Ph. Avouris, Science 253, 173 (1991); D. M. Eigler, C. P. Lutz, and W. E. Rudge, Nature (London) 352, 600 (1991); H. J. Hamin, S. Chiang, H. Birk, P. H. Guethner, and D. Ruger, J. Vac. Sci. Technol. B 9, 1398 (1991); M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993); Ph. Ebert, M. G. Lagally, and K. Urban, Phys. Rev. Lett. 70, 1437 (1993); H. Uchida, D. Huang, F. Grey, and M. Aono, Phys. Rev. Lett. 70, 2040 (1993); Ph. Avouris, I.-W. Lyo, and Y. Hasegawa, J. Vac. Sci. Technol. A 11, 1725 (1993); C. T. Sailing and M. G. Lagally, Surf. Sci. 265, 502 (1994).
11. In the early time of band calculations, a gedanken experiment was often performed: plot the band widths as a function of lattice constant ranging from infinite to finite values, and clarify how bands originate from atomic levels, e.g., W. Shockley, Electrons and Holes in Semiconductors (Van Nostrand, Princeton, 1950) or J. C. Slater, Quantum Theory of Matter, (McGraw-Hill, New York, 1968). It has been recognized since then that the band structure can be modified by manipulation of the lattice constant. Due to the current development of atom manipulation technology, it is becoming possible to pursue this idea and proceed to atomic wire electronics.
12. In the early time of band calculations, a gedanken experiment was often performed: plot the band widths as a function of lattice constant ranging from infinite to finite values, and clarify how bands originate from atomic levels, e.g., W. Shockley, Electrons and Holes in Semiconductors (Van Nostrand, Princeton, 1950) or J. C. Slater, Quantum Theory of Matter, (McGraw-Hill, New York, 1968). It has been recognized since then that the band structure can be modified by manipulation of the lattice constant. Due to the current development of atom manipulation technology, it is becoming possible to pursue this idea and proceed to atomic wire electronics.
13. T. Yamada, Y. Takiguchi, D. Huang, and Y. Yamamoto, Atomic Wire Circuit Network and Method, US Patent 1995, pending; D. Huang and Y. Yamamoto, Jpn. J. Appl. Phys. 35, 3734 (1996).
14. T. Yamada, Y. Takiguchi, D. Huang, and Y. Yamamoto, Atomic Wire Circuit Network and Method, US Patent 1995, pending; D. Huang and Y. Yamamoto, Jpn. J. Appl. Phys. 35, 3734 (1996).
15. T. Yamada, Y. Yamamoto, and W. A. Harrison, J. Vac. Sci. Technol. B 14, 1243 (1996); T. Yamada and Y. Yamamoto, Phys. Rev. B 54, 1902 (1996).
16. T. Yamada, Y. Yamamoto, and W. A. Harrison, J. Vac. Sci. Technol. B 14, 1243 (1996); T. Yamada and Y. Yamamoto, Phys. Rev. B 54, 1902 (1996).
17. For potential between closed-shell atoms, R. G. Gordon and Y. S. Kim, J. Chem. Phys. 56, 3122 (1972).
18. For extention to open-shell atoms, W. A. Harrison and R. Sokel, J. Chem. Phys. 65, 379 (1976).
19. 8C. W. J. Beenakker and H. van Houten, in Solid State Physics, edited by Ehrenreich and D. Turnbull (Academic, San Diego, 1991), Vol. 44 and references therein.
20. 8C. W. J. Beenakker and H. van Houten, in Solid State Physics, edited by Ehrenreich and D. Turnbull (Academic, San Diego, 1991), Vol. 44 and references therein.
21. 8C. W. J. Beenakker and H. van Houten, in Solid State Physics, edited by Ehrenreich and D. Turnbull (Academic, San Diego, 1991), Vol. 44 and references therein.
22. 8C. W. J. Beenakker and H. van Houten, in Solid State Physics, edited by Ehrenreich and D. Turnbull (Academic, San Diego, 1991), Vol. 44 and references therein.
23. 8C. W. J. Beenakker and H. van Houten, in Solid State Physics, edited by Ehrenreich and D. Turnbull (Academic, San Diego, 1991), Vol. 44 and references therein.
24. 9T. Yamada, J. Vac. Sci. Technol. A (to be published).
25. S. M. Sze, Physics of Semiconductor Devices (Wiley, New York, 1981).
26. 11W. Shockley, Electrons and Holes in Semiconductors (Van Nostrand, Princeton, 1950).
27. J. A. Stroscio, R. M. Feenstra, and A. P. Fein, J. Vac. Sci. Technol. A 5, 838 (1987); J. A. Stroscio and R. M. Feenstra, in Methods of Experimental Physics, edited by J. A. Stroscio and W. J. Kaiser (Academic, San Diego, 1993), Vol. 27, Chap. 4.
28. J. A. Stroscio, R. M. Feenstra, and A. P. Fein, J. Vac. Sci. Technol. A 5, 838 (1987); J. A. Stroscio and R. M. Feenstra, in Methods of Experimental Physics, edited by J. A. Stroscio and W. J. Kaiser (Academic, San Diego, 1993), Vol. 27, Chap. 4.
29. K. C. Pandey, Phys. Rev. Lett. 47, 1913 (1981).
30. There is another idea, which is to allow the foreign atoms to create chemical bonds with the substrate atoms by choosing an appropriate combination of the foreign atoms and substrate atoms with a suitable crystal orientation, requiring the electronic states to be localized within wires (or arrays) having a energy spectrum well inside the surface band gap of the substrate, S. Watanabe, Y. A. Ono, T. Hashizume, Y. Wada, J. Yamauchi, and M. Tsukada, Phys. Rev. B 52, 10 768 (1996). It has to be emphasized that the band structure and the Fermi energy are generally different from those of an isolated wire. The wire and the substrate are unified electronically, and all the physical properties have to be designed for the entire system. For example, the creation of a second wire or the small fluctuation in substrate doping may alter the properties of the original wire completely. However, this route may open the door to higher temperature operation due to the excellent mechanical stability of the wire.
31. C. Kittel, Introduction to Solid State Physics, 5th ed. (Wiley, New York, 1976).
32. J. Bardeen, Phys. Rev. 71, 717 (1947).
33. 18For the group velocity picture, see H.-F. Chueng, Y. Gefen, E. K. Riedel, and W.-H. Shih, Phys. Rev. B 37, 6050 (1988;), and for the transmission picture, see Y. Imry, in Directions in Condensed Matter Physics, edited by G. Grinstein and G. Mazenko (World Scientific, Singapore, 1986) Vol. 1; R. Landauer, Z. Phys. B 68, 217 (1987); M. Büttiker, Phys. Rev. Lett. 57, 1761 (1986).
34. 18For the group velocity picture, see H.-F. Chueng, Y. Gefen, E. K. Riedel, and W.-H. Shih, Phys. Rev. B 37, 6050 (1988;), and for the transmission picture, see Y. Imry, in Directions in Condensed Matter Physics, edited by G. Grinstein and G. Mazenko (World Scientific, Singapore, 1986) Vol. 1; R. Landauer, Z. Phys. B 68, 217 (1987); M. Büttiker, Phys. Rev. Lett. 57, 1761 (1986).
35. 18For the group velocity picture, see H.-F. Chueng, Y. Gefen, E. K. Riedel, and W.-H. Shih, Phys. Rev. B 37, 6050 (1988;), and for the transmission picture, see Y. Imry, in Directions in Condensed Matter Physics, edited by G. Grinstein and G. Mazenko (World Scientific, Singapore, 1986) Vol. 1; R. Landauer, Z. Phys. B 68, 217 (1987); M. Büttiker, Phys. Rev. Lett. 57, 1761 (1986).
36. 18For the group velocity picture, see H.-F. Chueng, Y. Gefen, E. K. Riedel, and W.-H. Shih, Phys. Rev. B 37, 6050 (1988;), and for the transmission picture, see Y. Imry, in Directions in Condensed Matter Physics, edited by G. Grinstein and G. Mazenko (World Scientific, Singapore, 1986) Vol. 1; R. Landauer, Z. Phys. B 68, 217 (1987); M. Büttiker, Phys. Rev. Lett. 57, 1761 (1986).
37. 18For the group velocity picture, see H.-F. Chueng, Y. Gefen, E. K. Riedel, and W.-H. Shih, Phys. Rev. B 37, 6050 (1988;), and for the transmission picture, see Y. Imry, in Directions in Condensed Matter Physics, edited by G. Grinstein and G. Mazenko (World Scientific, Singapore, 1986) Vol. 1; R. Landauer, Z. Phys. B 68, 217 (1987); M. Büttiker, Phys. Rev. Lett. 57, 1761 (1986).
38. 18For the group velocity picture, see H.-F. Chueng, Y. Gefen, E. K. Riedel, and W.-H. Shih, Phys. Rev. B 37, 6050 (1988;), and for the transmission picture, see Y. Imry, in Directions in Condensed Matter Physics, edited by G. Grinstein and G. Mazenko (World Scientific, Singapore, 1986) Vol. 1; R. Landauer, Z. Phys. B 68, 217 (1987); M. Büttiker, Phys. Rev. Lett. 57, 1761 (1986).
39. How the group velocity and the transmission pictures are related to give a consistent, unified description for the current magnitude is left for future study. The general shape of the I-V characteristics is steplike, and a detailed model will just address how much the current and voltage steps are, respectively, in the limit of intermediate particle exchange. Those details are not of interest here.
40. U. Landman, W. D. Luedtke, N. A. Burnham, and R. J. Colton, Science 248, 454 (1990); C. J. Muller, J. van Ruitenbeek, and L. J. de Jongh, Phys. Rev. Lett. 69, 140 (1992); L. Olesen, E. Laegsgaard, I. Stensgaard, F. Besebbacher, J. Schiøtz, P. Stoltze, K. W. Jacobsen, and J. K. Nørskov, Phys. Rev. Lett. 72, 2251 (1994); J. M. Krans, J. M. Van Ruitenbeek, V. V. Fisun, I. K. Yanson, and L. and J. De Jongh, Nature (London) 375, 767 (1995); J. L. Costa-Krämer, N. García, P. García-Mochales, and P. A. Serena, Surf. Sci. 342, L1144 (1995); J. I. Pascual, J. Méndez, J. Gómez-Herrero, A. B. Baró, N. Garcia, Uzi Landman, W. D. Luedtke, E. N. Bogachek, and H.-P. Cheng, Science 267, 1793 (1995).
41. U. Landman, W. D. Luedtke, N. A. Burnham, and R. J. Colton, Science 248, 454 (1990); C. J. Muller, J. van Ruitenbeek, and L. J. de Jongh, Phys. Rev. Lett. 69, 140 (1992); L. Olesen, E. Laegsgaard, I. Stensgaard, F. Besebbacher, J. Schiøtz, P. Stoltze, K. W. Jacobsen, and J. K. Nørskov, Phys. Rev. Lett. 72, 2251 (1994); J. M. Krans, J. M. Van Ruitenbeek, V. V. Fisun, I. K. Yanson, and L. and J. De Jongh, Nature (London) 375, 767 (1995); J. L. Costa-Krämer, N. García, P. García-Mochales, and P. A. Serena, Surf. Sci. 342, L1144 (1995); J. I. Pascual, J. Méndez, J. Gómez-Herrero, A. B. Baró, N. Garcia, Uzi Landman, W. D. Luedtke, E. N. Bogachek, and H.-P. Cheng, Science 267, 1793 (1995).
42. U. Landman, W. D. Luedtke, N. A. Burnham, and R. J. Colton, Science 248, 454 (1990); C. J. Muller, J. van Ruitenbeek, and L. J. de Jongh, Phys. Rev. Lett. 69, 140 (1992); L. Olesen, E. Laegsgaard, I. Stensgaard, F. Besebbacher, J. Schiøtz, P. Stoltze, K. W. Jacobsen, and J. K. Nørskov, Phys. Rev. Lett. 72, 2251 (1994); J. M. Krans, J. M. Van Ruitenbeek, V. V. Fisun, I. K. Yanson, and L. and J. De Jongh, Nature (London) 375, 767 (1995); J. L. Costa-Krämer, N. García, P. García-Mochales, and P. A. Serena, Surf. Sci. 342, L1144 (1995); J. I. Pascual, J. Méndez, J. Gómez-Herrero, A. B. Baró, N. Garcia, Uzi Landman, W. D. Luedtke, E. N. Bogachek, and H.-P. Cheng, Science 267, 1793 (1995).
43. U. Landman, W. D. Luedtke, N. A. Burnham, and R. J. Colton, Science 248, 454 (1990); C. J. Muller, J. van Ruitenbeek, and L. J. de Jongh, Phys. Rev. Lett. 69, 140 (1992); L. Olesen, E. Laegsgaard, I. Stensgaard, F. Besebbacher, J. Schiøtz, P. Stoltze, K. W. Jacobsen, and J. K. Nørskov, Phys. Rev. Lett. 72, 2251 (1994); J. M. Krans, J. M. Van Ruitenbeek, V. V. Fisun, I. K. Yanson, and L. and J. De Jongh, Nature (London) 375, 767 (1995); J. L. Costa-Krämer, N. García, P. García-Mochales, and P. A. Serena, Surf. Sci. 342, L1144 (1995); J. I. Pascual, J. Méndez, J. Gómez-Herrero, A. B. Baró, N. Garcia, Uzi Landman, W. D. Luedtke, E. N. Bogachek, and H.-P. Cheng, Science 267, 1793 (1995).
44. U. Landman, W. D. Luedtke, N. A. Burnham, and R. J. Colton, Science 248, 454 (1990); C. J. Muller, J. van Ruitenbeek, and L. J. de Jongh, Phys. Rev. Lett. 69, 140 (1992); L. Olesen, E. Laegsgaard, I. Stensgaard, F. Besebbacher, J. Schiøtz, P. Stoltze, K. W. Jacobsen, and J. K. Nørskov, Phys. Rev. Lett. 72, 2251 (1994); J. M. Krans, J. M. Van Ruitenbeek, V. V. Fisun, I. K. Yanson, and L. and J. De Jongh, Nature (London) 375, 767 (1995); J. L. Costa-Krämer, N. García, P. García-Mochales, and P. A. Serena, Surf. Sci. 342, L1144 (1995); J. I. Pascual, J. Méndez, J. Gómez-Herrero, A. B. Baró, N. Garcia, Uzi Landman, W. D. Luedtke, E. N. Bogachek, and H.-P. Cheng, Science 267, 1793 (1995).
45. U. Landman, W. D. Luedtke, N. A. Burnham, and R. J. Colton, Science 248, 454 (1990); C. J. Muller, J. van Ruitenbeek, and L. J. de Jongh, Phys. Rev. Lett. 69, 140 (1992); L. Olesen, E. Laegsgaard, I. Stensgaard, F. Besebbacher, J. Schiøtz, P. Stoltze, K. W. Jacobsen, and J. K. Nørskov, Phys. Rev. Lett. 72, 2251 (1994); J. M. Krans, J. M. Van Ruitenbeek, V. V. Fisun, I. K. Yanson, and L. and J. De Jongh, Nature (London) 375, 767 (1995); J. L. Costa-Krämer, N. García, P. García-Mochales, and P. A. Serena, Surf. Sci. 342, L1144 (1995); J. I. Pascual, J. Méndez, J. Gómez-Herrero, A. B. Baró, N. Garcia, Uzi Landman, W. D. Luedtke, E. N. Bogachek, and H.-P. Cheng, Science 267, 1793 (1995).
46. N. D. Lang, Phys. Rev. Lett. 56, 1164 (1986).
47. N. D. Lang, Phys. Rev. B 52, 5335 (1995).
48. W. Shockley, Phys. Rev. 56, 317 (1939).