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Confinamiento dieléctrico 207152 J.L. Movilla, J. Planelles / Computer Physics Communications 170 (2005) 144–152We find that when the QD is embedded in a medium with a low dielectric constant (as air or a vacuum) the polarizationpotential yields an energy stabilization that increase with the impurity off-centering. Dielectric constantsclose to ǫ i = 3 (for ǫ o = 1) and relatively large QD effective masses yield the largest impurity off-centering energyeffects. Self-energy and surrounding effective masses larger than the QD ones emphasize these effects, althoughtheir interplay is highly non-additive.As the dielectric off-centering stabilization will compete against the spatial confining off-centering destabilization,in some situations it will be difficult to predict aprioriwhether the most stabilizing impurity position willbe the QD center or not. This fact emphasizes the relevance of employing computational codes which include allconfining sources in a balanced way.References[1] H.J. Queisser, E.E. Haller, Science 281 (1998) 945.[2] J.L. Movilla, J. Planelles, Phys. Rev. B 71 (2005) 075319.[3] Z.Y. Deng, J.K. Guo, T.R. Lai, J. Phys.: Condens. Matter 6 (1994) 5949.[4] L.E. Brus, J. Chem. Phys. 80 (1984) 4403.[5] R.Tsu,D.Babić, Appl. Phys. Lett. 64 (1994) 1806.[6] R. Tsu, Microelectron. J. 34 (2003) 329.[7] G. Allan, C. Deleure, M. Lannoo, E. Martin, Phys. Rev. B 52 (1995) 11982.[8] G. Goldoni, F. Rossi, E. Molinari, Phys. Rev. Lett. 80 (1998) 4995.[9] G. Goldoni, F. Rossi, A. Orlandi, M. Rontani, F. Manghi, E. Molinari, Physica E 6 (2000) 482.[10] A. Orlandi, M. Rontani, G. Goldoni, F. Manghi, E. Molinari, Phys. Rev. B 63 (2001) 045310.[11] M. Iwamatsu, K. Horii, Jpn. J. Appl. Phys. 36 (1997) 6416.[12] M. Iwamatsu, M. Fujiwara, N. Happo, K. Horii, J. Phys.: Condens. Matter 9 (1997) 9881.[13] J.L. Zhu, X. Chen, J. Phys.: Condens. Matter 6 (1994) L123.[14] A. Corella-Madueño, R. Rosas, J.L. Marín, R. Riera, J. Appl. Phys. 90 (2001) 2333.[15] N. Porras-Montenegro, S.T. Pérez-Merchancano, A. Latgé, J. Appl. Phys. 74 (1993) 7624.[16] N. Porras-Montenegro, S.T. Pérez-Merchancano, Phys. Rev. B 46 (1992) 9780.[17] J.M. Ferreyra, C.R. Proetto, Phys. Rev. B 52 (1995) R2309.[18] J.M. Ferreyra, P. Bosshard, C.R. Proetto, Phys. Rev. B 55 (1997) 13682.[19] J.L. Zhu, J.J. Xion, B.L. Gu, Phys. Rev. B 41 (1990) 6001.[20] V. Ranjan, V.A. Singh, J. Appl. Phys. 89 (2001) 6415.[21] D. BenDaniel, C.B. Duke, Phys. Rev. 152 (1966) 683.[22] P.G. Bolcatto, C.R. Proetto, J. Phys.: Condens. Matter 13 (2001) 319.[23] G. Arfken, Mathematical Methods for Physicists, Academic Press, San Diego, 1985.[24] P.G. Bolcatto, C.R. Proetto, Phys. Stat. Sol. (b) 220 (2000) 191.[25] L. Bányai, S.W. Koch, Semiconductor Quantum Dots, World Scientific, Singapore, 1993.[26] P. Harrison, Quantum Wells, Wires and Dots, John Wiley and Sons, Chichester, 2001.[27] W.E. Arnoldi, Quart. J. Appl. Math. 9 (1951) 17;Y. Saad, Numerical Methods for large Scale Eigenvalue Problems, Halsted Press, New York, 1992;R.B. Morgan, Math. Comp. 65 (1996) 1213.[28] R.B. Lehoucq, D.C. Sorensen, P.A. Vu, C. Yang, ARPACK: Fortran subroutines for solving large scale eigenvalue problems, Release 2.1;R.B. Lehoucq, D.C. Sorensen, C. Yang, ARPACK User’s Guide: Solution of Large-Scale Eigenvalue Problems with Implicit RestartedArnoldi Methods, SIAM, Philadelphia, PA, 1998.[29] For a given QD material, these are the environments that maximize the effect of the induced charge, as can be inferred from φ B , φ C ,andφ E polarization terms of the coulombic potential φ c (Eqs. (8), (9), and (11)).[30] We must point out that an increase of ǫ i not always turns into a screening of the off-centering stabilization capability. In particular, ifǫ o = 1, this is true for ǫ i > 3.