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Lateral quantum wells at vicinal Au(111) studied with angle-resolved photoemission

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Electrons at noble metal surfaces can be confined within terraces leading to one-dimensional surface states. These can be studied with angle-resolved photoemission from vicinal surfaces with regular arrays of (111)-oriented terraces. Here we show the case of Au(23 23 21), which is vicinal to Au(111) and displays L=56 Angstrom wide terraces. The surface state band appears broken up into three quantum well levels that match to those of the infinite quantum well of the same width L. Their parallel momentum dependent photoemission intensity allows mapping the probability density of the confined wave function in reciprocal space using angle-resolved photoemission. By Fourier transformation, their respective experimental wave functions in real space are obtained and compared to the case of the infinite quantum-well, showing excellent agreement. Final state step superlattice diffraction effects have also been observed. Finally, we observe the quenching of the characteristic spin-orbit coupling of Au(111) in the confinement direction. This is another indication of the one-dimensional character of the surface state, as confirmed with first order perturbation theory.
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© 2002 The American Physical Society. E.V.C. thanks P.M. Echenique for fruitful discussions. A.Mu., F.J.G. de A., E.V.C., Y.M.K., and J.E.O. are supported by the Universidad del País Vasco (Grant No. 1/UPV/ EHU/00057.240-EA-8078/2000). V.R. and S.R. are supported by the CNRS-ULTIMATECH program, the CRIF and the Université de Paris 7. A. Ma. was supported by Contract No. HPMF-CT-2000-00565. The experiments at the SRC were supported by NSF Grants No. DMR-0084402, DMR-9704196, and DMR-9815416.
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1. F. J. Himpsel, J. E. Ortega, G. J. Mankey, and R. F. Willis, Adv. Phys. 47, 511 (1998). 2. R. Nötzel and K. H. Ploog, Adv. Mater. 522, (1993); R. Nötzel, Z. Niu, M. Ramsteimer, H. P. Schönherr, A. Trampert, L. Däweritz, and K. H. Ploog, Natur (London! 392, 56 (1998); P. Segovia, D. Purdie, M. Hegsberger, and Y. Baer, ibid. 402, 504 (1999); P. Gambardella, A. Dellmeyer, K. Maiti, M. C. Malagoli, W. Eberhardt, K. Kern, and C. Carbone, ibid. 416, 301 (2002). 3. J. E. Ortega, S. Speller, A. Bachmann, A. Mascaraque, E. G. Michel, A. Mugarza, A. Närmann, A. Rubio, and F. J. Himpsel, Phys. Rev. Lett. 84, 6110 (2000). 4. A. Mugarza, A. Mascaraque, V. Pérez-Dieste, V. Repain, S. Rousset, F. J. García de Abajo, and J. E. Ortega, Phys. Rev. Lett. 87, 107601 (2001). 5. J. E. Ortega, A. Mugarza, V. Repain, S. Rousset, V. Pérez-Dieste, and A. Mascaraque, Phys. Rev. B 65, 165413 (2002). 6. F. Baumberger, T. Greber, and J. Osterwalder, Phys. Rev. B 64, 195411 (2001). 7. X. Y. Wang, X. J. Shen, and R. M. Osgood, Jr., Phys. Rev. B 56, 7665 (1997). 8. Ph. Avouris and I.-W. Lyo, Science 264, 942 (1994). 9. L. Buürgi, O. Jeandupeux, A. Hirstein, H. Brune, and K. Kern, Phys. Rev. Lett. 81, 5370 (1998). 10. M. Giesen and T. L. Einstein, Surf. Sci. 449, 191 (2000). 11. V. Repain, J. M. Berroir, B. Croset, S. Rousset, Y. Garreau, V. H. Etgens, and L. Lecoeur, Phys. Rev. Lett. 84, 5367 (2000). 12. T. Abukawa, M. Sasaki, F. Hisamatsu, T. Goto, T. Kinoshita, A. Kakizaki, and S. Kono, Surf. Sci. 325, 33 (1995). 13. R. Paniago, R. Matzdorf, G. Meister, and A. Goldmann, Surf. Sci. 336, 113 (1995). 14. F. Reinert, G. Nicolay, S. Schmidt, D. Ehm, and S. Hüfner, Phys. Rev. B 63, 115415 (2001). 15. S. LaShell, B. A. McDougall, and E. Jensen, Phys. Rev. Lett. 77, 3419 (1996). 16. J. Kliewer, R. Berndt, E. V. Chulkov, V. M. Silkin, P. M. Echenique, and S. Crampin, Science 288, 1399 (2000). 17. Note that, in the Fabry-Pe´rot model of Ref. 9 absorption is included, thus the reflectivity uRu 2,1 obtained by this group is still consistent with no transmission throughout the steps. This is reinforced by the fact that they obtained a phase w52p, a condition implying total reflectivity if absorption is not taken into account. 18. M. F. Crommie, C. P. Lutz, and D. M. Eigler, Science 262, 218 (1993). 19. E. J. Heller, M. F. Crommie, C. P. Lutz, and D. M. Eigler, Nature (London) 369, 464 (1994). 20. S. Crampin, N. H. Boon, and J. E. Inglesfield, Phys Rev. Lett. 73, 1015 (1994). 21. G. Hörmandinger, and J. B. Pendry, Phys. Rev. B 50, 18 607 (1994). 22. Value obtained from LDA-PW band calculations by Angel Rubio. 23. M. Henzeler, Surf. Sci. 19, 159 (1970). 24. A. Mugarza, J. E. Ortega, and F. J. García de Abajo, cond-mat/0208254 (unpublished). 25. The case of spin-orbit splitting of standing waves extending from a single step on a flat surface along the normal to the step was studied by Petersen and Hedegård (Ref. 27), who showed that the spin-orbit splitting cannot be observed in surface state standing waves at the Fermi level with the Fourier transform STM method. Here we give a more transparent and complete insight of this problem. 26. Yu. M. Koroteev, E. V. Chulkov, and P. M. Echenique (unpublished). 27. L. Petersen and P. Hedega˚rd, Surf. Sci. 459, 49 (2000). 28. E. V. Chulkov, V. M. Silkin, and P. M. Echenique, Surf. Sci. 437, 330 (1999). 29. E. V. Chulkov, V. M. Silkin, and M. Machado, Surf. Sci. 482-485, 693 (2001). 30. E. V. Chulkov, V. M. Silkin, and E. N. Shirykalov, Surf. Sci. 188, 287 (1987). Surface Electronic-Structure, Metal-Surfaces, State Electrons, Spin, Temperature, Confinement, Cu(111), Corrals, Terrace, Arrays
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