Use of an alkali halide molecule as a field-effect transistor

Physical Review B - Condensed Matter and Materials Physics

Volumn 64, Issue 23, 2001, Pages

  Lang, N D ^a  

^a IBM T J WATSON RESEARCH CENTER   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

HALIDE;

ARTICLE; CALCULATION; CONDUCTANCE; ELECTRODE; ELECTRONICS; ENERGY; MOLECULAR MODEL;

EID: 0035894235     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.64.235121     Document Type: Article

References (22)

1. M. Di Ventra, S T. Pantelides, and N D. Lang, Appl. Phys. Lett.76, 3448 (2000).
2. Cf. also J. Taylor, H. Guo, and J. Wang, Phys. Rev. B63, 121104 (2001).
3. Cf. J. Chen, M A. Reed, A M. Rawlett, and J M. Tour, Science286, 1550 (1999).
4. A. Hopkinson, C P. Lutz, and D M. Eigler (private communication).
5. N D. Lang and Ph. Avouris, Phys. Rev. B64, 125323(2001);
6. N D. LangPh. AvourisPhys. Rev. Lett.81, 3515 (1998);
7. Phys. Rev. Lett.N D. LangPh. Avouris84, 358 (2000).
8. See the discussion of V. Kalmeyer and R B. Laughlin, Phys. Rev. B35, 9805 (1987);
9. Phys. Rev. BN D. Lang, 55, 4113 (1997).
10. See, e.g., K. Nagesha and L. Sanche, Phys. Rev. Lett.81, 5892 (1998);
11. Phys. Rev. Lett.J E. Demuth, D. Schmeisser, and Ph. Avouris, 47, 1166 (1981).
12. See, e.g., N D. Lang, in Theory of the Inhomogeneous Electron Gas, edited by S. Lundqvist and N.H. March (Plenum Press, New York, 1983), p. 309.
13. In the calculations, we take the electrodes to have (formula presented), typical of a high-electron-density metal such as Al. Here (formula presented), with n the mean interior electron number density in the electrodes.
14. (formula presented).
15. The disks were taken to have a radius of 7 a.u. and a spacing of 16 a.u. (The exact values are not important.)
16. N D. Lang, Phys. Rev. B52, 5335 (1995).
17. This means that the Fermi levels of the right and left electrodes differ by 0.01 eV; since this is so small, we will not make a distinction between the two Fermi levels when, for example, we speak of the state density at the Fermi level.
18. By density of states we mean the difference in density of energy eigenstates between two systems: the pair of electrodes together with the molecule linking them, and the same pair of electrodes (with the same spacing) without the molecule. The eigenstates referred to are those of the single-particle equations of the density-functional formalism.
19. This implies that the molecule acquires somewhat of a negative charge, as was seen also in Refs. 2 and 5.
20. The conductance we refer to is the additional conductance due to the presence of the molecule, i.e., the difference in conductance of the system with and without the molecule. (Whether or not the biased gate electrodes are included in the calculation for the system without the molecule was verified to be unimportant.)
21. The bond length of the molecule will change somewhat in response to the gate field, an effect which we do not include in the calculation shown in Fig. 55. (We hold the bond length fixed at the value for the free molecule.) In order to test how important this approximation is, a calculation of the bond length in the presence of a uniform field of (formula presented) with the polarity used here was done for the free molecule, using GAUSSIAN 98 (SVWN5, LanL2DZ basis set: Revision A.6, M.J. Frisch, et al., Gaussian, Inc., Pittsburgh PA, 1998), which gave a decrease in bond length of (formula presented). Redoing our self-consistent molecule-electrode calculations with this decrease in bond length gives a conductance within (formula presented) of the value shown in Fig. 55.
22. Reciprocal of the conductance is defined in Ref. 16.