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Different formulations of the field-to-transmission-line coupling equations are reviewed and discussed. An equivalent formulation is derived in which the source terms (or forcing functions) are expressed in terms of the magnetic excitation field. This form ...
In this Thesis we study several aspects of potential scattering in non-relativistic quantum mechanics. In the first part, we study the concept of time delay. More precisely, after an elementary introduction to the theory (chapter I), we clarify in chapter ...
A magneto-optical study of accepters in varying degrees of confinement in GaAs/Al-x Ga-l-x, As quantum wells (QW's) is presented. A model for the splitting of the acceptor bound exciton (BE) and the allowed BE transitions in the presence of a magnetic fiel ...
We report on time-resolved photoluminescence studies of charged and neutral excitons in a modulation doped GaAs quantum well under resonant excitation and high magnetic field. The radiative lifetime of the charged exciton is rather short, 60 ps at zero hel ...
It is shown by theory and expt. how coherent superpositions of quantum states in 3-level systems can be manipulated by irradiating 2 connected transitions with 2 resonant fields with suitably shaped time-dependent amplitudes and phases. Three variants are ...
Quantum wire heterostructures, such as V- and T-shaped wires, are very promising candidates for low-threshold lasing. A crucial issue is the excitonic vs. free-carrier nature of the radiative recombination. Here, we report on magnetophotoluminescence studi ...
Electronic states bound to impurities located in the quantum well barriers are calculated when the bulk binding energy is comparable to the quantum well depth. We show the existence of a complex level pattern due to the interaction between barrierlike stat ...
We consider the density of states of Schr6dmger operators with a uniform magnetic field and a random potential with a Gaussian distribution. We show that the restriction to the states of the first Landau level is eqmvalent to a scaling hmit where one looks ...
A silicon-based temperature stabilized axial Hall probe with an absolute accuracy of +/-40 ppm in the full range between 0 and 6 T is presented. The absolute calibration of the probe is performed against a nuclear magnetic resonance (NMR) probe. The applic ...
The temperature dependence of the critical current density has been studied in magnetic fields up to 12 T for Bi-2212/Ag round wires. In short specimens critical current densities of more than 10000 A/cm(2) have been achieved at 20 K and B = 8 T. In the ca ...
