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High-temperature expansion for short-range order of adsorbates with dipolar repulsive interaction
A455 405
Surface Science 253 (1991) 405-415 North-Holland
High-temperature expansion for short-range order of adsorbates with dipolar repulsive interaction K. Kaldtani, H. Kobayashi and A. Yoshimori Department of Material Physics, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka 560, Japan Received 22 November 1990; accepted for publication 14 January 1991 A set of approximate integral equations for the two-adsorbate correlation function in an adsorbate system with a repulsive dipolar interaction is proposed on the basis of the high-temperature expansion series at very low coverages in the disorder state. This set of equations is solved numerically to obtain the correlation functions as a function of temperature and coverage. The set of integral equations are discussed in a lattice version of the Kirkwood method for a liquid.
416
Surface Science 253 (1991) 416-428 North-Holland
Electromagnetic surface waves on a free-electron-like medium in the presence of a DC current: the dispersion relation O. Keller, A. Liu and J.H. Pedersen Institute of Physics, University of Aalborg, Pontoppidanstrcede 103, DK-9220 Aalborg Ost, Denmark Received 7 November 1990; accepted for publication 14 February 1991 Within the framework of the so-called semiclassical infinite-barrier (SCIB) model, a non-local dispersion relation for electromagnetic surface waves (SEWs) on a free-electron-like medium in which a DC current is flowing is established. When the drift velocity of the carriers has a non-zero component along an axis perpendicular to the plane of propagation of the SEWs, our new dispersion relation predicts the existence of surface waves with a mixed state of s- and p-polarizations. Limiting ourselves to the hydrodynamic approximation, which allows the presence of collective excitations in the electron gas only, and to the case where the drift velocity is parallel to the propagation direction of the surface waves, we have carried out an elaborated study of the p-polarized SEW dispersion relation. A numerical calculation of the six branches of the dispersion relation has been carried out for n-InSb. Our calculations show that the "local" surface polaritons and the "electrostatic" surface plasmons in the presence of the DC current interact in the frequency regime ~pV/c~o/(E~o + 1) _<~ ~ ~pV/C~o/(c~ - 1). Significant modifications of some of the branches of the dispersion relation are found including new connections of branches. For certain frequencies the dispersion relation obtained predicts the existence of SEW instabilities.
Surface Science 253 (1991) 405-415 North-Holland
High-temperature expansion for short-range order of adsorbates with dipolar repulsive interaction K. Kaldtani, H. Kobayashi and A. Yoshimori Department of Material Physics, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka 560, Japan Received 22 November 1990; accepted for publication 14 January 1991 A set of approximate integral equations for the two-adsorbate correlation function in an adsorbate system with a repulsive dipolar interaction is proposed on the basis of the high-temperature expansion series at very low coverages in the disorder state. This set of equations is solved numerically to obtain the correlation functions as a function of temperature and coverage. The set of integral equations are discussed in a lattice version of the Kirkwood method for a liquid.
416
Surface Science 253 (1991) 416-428 North-Holland
Electromagnetic surface waves on a free-electron-like medium in the presence of a DC current: the dispersion relation O. Keller, A. Liu and J.H. Pedersen Institute of Physics, University of Aalborg, Pontoppidanstrcede 103, DK-9220 Aalborg Ost, Denmark Received 7 November 1990; accepted for publication 14 February 1991 Within the framework of the so-called semiclassical infinite-barrier (SCIB) model, a non-local dispersion relation for electromagnetic surface waves (SEWs) on a free-electron-like medium in which a DC current is flowing is established. When the drift velocity of the carriers has a non-zero component along an axis perpendicular to the plane of propagation of the SEWs, our new dispersion relation predicts the existence of surface waves with a mixed state of s- and p-polarizations. Limiting ourselves to the hydrodynamic approximation, which allows the presence of collective excitations in the electron gas only, and to the case where the drift velocity is parallel to the propagation direction of the surface waves, we have carried out an elaborated study of the p-polarized SEW dispersion relation. A numerical calculation of the six branches of the dispersion relation has been carried out for n-InSb. Our calculations show that the "local" surface polaritons and the "electrostatic" surface plasmons in the presence of the DC current interact in the frequency regime ~pV/c~o/(E~o + 1) _<~ ~ ~pV/C~o/(c~ - 1). Significant modifications of some of the branches of the dispersion relation are found including new connections of branches. For certain frequencies the dispersion relation obtained predicts the existence of SEW instabilities.