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1993

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Order And Chaos In Semiconductor Microstructures, W. A. Lin, John B. Delos, Robert E. Jensen Oct 1993

Order And Chaos In Semiconductor Microstructures, W. A. Lin, John B. Delos, Robert E. Jensen

Arts & Sciences Articles

The semiclassical theory of ballistic electron transport in semiconductor microstructures provides a description of the quantum conductance fluctuations in terms of the classical distributions for the lengths and directed areas of the scattering trajectories. Because the classical dynamics differs for integrable (circular) and chaotic (stadium) scattering domains, experimental measurements of the conductance of these microstructures provide a unique probe of the quantum properties of classically regular and chaotic systems. To advance these theoretical and experimental studies we compare geometrical formulas for the classical distributions of lengths and areas with numerical simulations for microstructures examined in recent experiments, we assess the …


Photoabsorption Spectra Of Atoms In Parallel Electric And Magnetic Fields, J. M. Mao, K. A. Rapelje, S. J. Blodgett-Ford, John B. Delos, A. König, H. Rinneberg Sep 1993

Photoabsorption Spectra Of Atoms In Parallel Electric And Magnetic Fields, J. M. Mao, K. A. Rapelje, S. J. Blodgett-Ford, John B. Delos, A. König, H. Rinneberg

Arts & Sciences Articles

Measurements have been made of the absorption spectrum of Ba from the 6s6p 1P1 level to states near the ionization threshold in parallel electric and magnetic fields. The absorption spectrum shows oscillations superposed on a smooth background. Each oscillation is correlated with a closed orbit of the electron. At strong electric fields, trajectories are regular, and closed orbits form orderly patterns. For weak electric fields, trajectories are chaotic, and many more closed orbits are present. Many of these are produced by bifurcations as the electric field is reduced.


Photodetachment Cross Section Of H- In Crossed Electric And Magnetic Fields. Ii. Quantum Formulas And Their Reduction To The Result Of The Closed-Orbit Theory, Aaron D. Peters, John B. Delos Apr 1993

Photodetachment Cross Section Of H- In Crossed Electric And Magnetic Fields. Ii. Quantum Formulas And Their Reduction To The Result Of The Closed-Orbit Theory, Aaron D. Peters, John B. Delos

Arts & Sciences Articles

In this, the second of two papers, we derive general quantum formulas for the photodetachment cross section for H− in perpendicular electric and magnetic fields. The results are valid for any polarization and can be reduced to the semiclassical results of the first paper [A. D. Peters and J. B. Delos, Phys. Rev. A 47, 3020 (1993)]: a smooth background plus oscillatory terms. This connection between the quantum and semiclassical results is made using a stationary-phase approximation and it is shown that each stationary-phase point corresponds to a closed orbit.


Photodetachment Cross Section Of H- In Crossed Electric And Magnetic Fields. I. Closed-Orbit Theory, Aaron D. Peters, John B. Delos Apr 1993

Photodetachment Cross Section Of H- In Crossed Electric And Magnetic Fields. I. Closed-Orbit Theory, Aaron D. Peters, John B. Delos

Arts & Sciences Articles

In this, the first of two papers, we obtain a simple analytic formula for the photodetachment cross section of H− in crossed electric and magnetic fields. The three-dimensional semiclassical approximation predicts oscillations in the spectrum and these oscillations are correlated with closed classical orbits. In the following paper [A. D. Peters and J. B. Delos, Phys. Rev. A 47, 3036 (1993)] we derive fully-quantum-mechanical formulas for the cross section in perpendicular electric and magnetic fields and show how these results can be reduced to the semiclassical results of this paper.