References of "Wirtz, Ludger 50003339"
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See detailInteraction of highly charged ions with microcapillaries
Tokesi, K.; Wirtz, Ludger UL; Burgdorfer, J.

in Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms (1999), 154(1-4), 307-311

We analyze the transmission of highly charged ions (HCI) through microcapillaries. The interaction of an HCI with the interval surface of the capillary is treated within the framework of linear response ... [more ▼]

We analyze the transmission of highly charged ions (HCI) through microcapillaries. The interaction of an HCI with the interval surface of the capillary is treated within the framework of linear response. In the limiting case of an ideal conducting cylindrical surface, the interaction reduces to a classical image potential. For Neq+ projectiles transmitting through a Ni capillary calculations for the impact parameter distribution and angular distribution of hollow atoms are presented. We find the fraction of transmitted projectiles which are partially neutralized in good agreement with recent experiments. (C) 1999 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailInteraction of highly charged ions with microcapillaries
Tokesi, K.; Wirtz, Ludger UL; Burgdorfer, J.

in PHYSICA SCRIPTA (1999), T80B

The transmission of highly charged ions (HCI) through microcapillaries is investigated. The interaction of an HCI with the internal surface of the capillary is described in terms of a classical image ... [more ▼]

The transmission of highly charged ions (HCI) through microcapillaries is investigated. The interaction of an HCI with the internal surface of the capillary is described in terms of a classical image potential. For Neq+ projectiles transmitted through a Ni capillary the impact parameter distribution and angular distribution of ions leaving the microcapillary is determined. We consider both a narrowly focussed and a dispersive incident beam relative to the acceptance angle of the capillary. Our results are compared with recent experiments. [less ▲]

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See detailGauge-invariant theory for semiclassical magnetotransport through ballistic microstructures
Wirtz, Ludger UL; Tang, J. Z.; Burgdorfer, J.

in Physical Review. B (1999), 59(4), 2956-2967

Within the semiclassical theory of magnetotransport through ballistic cavities, fluctuations in the transmission amplitude and in the conductance originate from the Aharonov-Bohm phase of directed areas ... [more ▼]

Within the semiclassical theory of magnetotransport through ballistic cavities, fluctuations in the transmission amplitude and in the conductance originate from the Aharonov-Bohm phase of directed areas. We formulate the semiclassical transmission amplitude in gauge-invariant form. The gauge invariant phases can be visualized in terms of areas enclosed by classical paths, which consist of the real path connecting the entrance point to the exit point and a virtual path leading back to the entrance point. We implement this method on different levels of a semiclassical description of magnetotransport with applications to magnetoconductance fluctuations and correlations. The validity of the semiclassical theories is analyzed. [S0163-1829(99)10903-2]. [less ▲]

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See detailThreshold for potential sputtering of LiF
Hayderer, G.; Schmid, M.; Varga, P. et al

in Physical Review Letters (1999), 83(19), 3948-3951

We have measured total sputtering yields for impact of slow (less than or equal to 100 eV) singly and doubly charged ions on LiF. The minimum potential energy necessary to induce potential sputtering (PS ... [more ▼]

We have measured total sputtering yields for impact of slow (less than or equal to 100 eV) singly and doubly charged ions on LiF. The minimum potential energy necessary to induce potential sputtering (PS) from UF was determined to be about 10 eV. This threshold coincides with the energy necessary to produce a cold hole in the valence band of LiF by resonant neutralization. This allows the first unambiguous identification of PS induced by cold holes. Further stepwise increase of the sputtering yield with higher projectile potential energies provides evidence for additional defect-mediated sputtering mechanisms operative in alkali halides. [less ▲]

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See detailOscillations in the magnetoconductance autocorrelation function for ballistic microstructures
Tang, J. Z.; Wirtz, Ludger UL; Burgdorfer, J. et al

in Physical Review. B, Condensed Matter (1998), 57(16), 9875-9878

We present a comparison between experiment and theory for the magnetoconductance autocorrelation function C(Delta B) for transport through a stadium-shaped ballistic microstructure. The correlation ... [more ▼]

We present a comparison between experiment and theory for the magnetoconductance autocorrelation function C(Delta B) for transport through a stadium-shaped ballistic microstructure. The correlation function displays damped oscillations which can be traced to the quantum interference between bundles of short trajectories. We present two different semiclassical calculations applicable for large and small mode numbers of the quantum wire, respectively. Good agreement is found with experimental data taken at relatively low mode numbers. [S0163-1829(98)03316-5]. [less ▲]

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See detailGeometry-dependent scattering through ballistic microstructures: Semiclassical theory beyond the stationary-phase approximation
Wirtz, Ludger UL; Tang, J. Z.; Burgdorfer, J.

in Physical Review. B (1997), 56(12), 7589-7597

The conductance of a ballistic microstructure shows strong fluctuations as a function of the Fermi wave number. We present a semiclassical-theory that describes these fluctuations in terms of bundles of ... [more ▼]

The conductance of a ballistic microstructure shows strong fluctuations as a function of the Fermi wave number. We present a semiclassical-theory that describes these fluctuations in terms of bundles of short trajectories. These trajectories provide the dominant contribution to electron transport through a weakly open microstructure. For the coupling between the quantum wires and the cavity, contributions beyond the stationary phase approximation are taken into account giving rise to diffraction effects. A comparison with full quantum calculations for st rectangular billiard is made. The peak positions of the power spectrum agree very well between the quantum and semiclassical theories. Numerical evidence is found for the breakdown of the semiclassical approximation for long paths. A simple explanation in terms of the dispersion of the semiclassical wave packet in the interior of the cavity is proposed. [less ▲]

Detailed reference viewed: 125 (3 UL)