Lateral localization

Two main glacial events are responsible for glacial dispersal from the MFN deposit a west to east Laurentide Ice Sheet flow (090°) and later local southwest to northeast (070°) ice flow. Both these glacial events were primarily erosive (Pronk etal. 1989 Parkhill Doiron 2003)... 

Related to the problem of missing frontal information is the so-called cone of confusion which describes the ambiguity of lateral localization when extreme left or right information is reproduced in the headphone assembly. See Fig. 3.69. 

Non-individualized systems are effective only up to 6 kHz and then only when the listener s position is known (Gardner, 1998). However, despite poor high-frequency performance, cross-talk-cancelled audio is capable of producing stunning, well externalized, virtual sounds to the sides of the listener using frontally placed loudspeakers. As a result of the listener s pinna cues, the sounds are well externalized. The sounds are shifted to the side as a result of the dominance of low-frequency time-delay cues in lateral localization the cross-talk cancellation works effectively at low frequencies to provide this cue. 

This analysis is thus consistent with the fact that excitons in the nonpolar QDs studied here are laterally localized inside the QDs, the decay time of each QD being related to the lateral localization of the exciton inside the QD and not to the QD size. This is confirmed by the experimental data presented in Figure 13.9. The luminescence decay curves are not monoexponential. 

The results are shown in Figure 13.15 in striking contrast with the decay curves for ensembles of QDs, the PL decay for single dots is well fitted by a single exponential. Various isolated QDs have different decay times, and these decay times are not correlated to the emission wavelength. These various decay times can be attributed to excitons that have different lateral localization surfaces inside each QD, this localization parameter being independent of QD size. 

Analyzing the temperature dependence of the PL line width in the framework of a quasi-2D wavefunction model and combining it with time-resolved PL experiments, it is concluded that excitons are laterally localized at a length scale smaller than the dot size. No direct correlation was found between monoexponential decay time constants and dot size. As a consequence, it appears that the localization of exciton itself does not simply depend on dot size, making the nature of localization in these nonpolar QDs an issue still open till date. 

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