Measuring the effective phonon density of states of a quantum dot

We employ detuning-dependent decay-rate measurements of a quantum dot in a photonic-crystal cavity to study the influence of phonon dephasing in a solid-state quantum-electrodynamics experiment. The experimental data agree with a microscopic non-Markovian model accounting for dephasing from longitudinal acoustic phonons, and identifies the reason for the hitherto unexplained difference between non-resonant cavity feeding in different nanocavities. From the comparison between experiment and theory we extract the effective phonon density of states experienced by the quantum dot. This quantity determines all phonon dephasing properties of the system and is found to be described well by a theory of bulk phonons.Comment: 5 pages, 3 figures, submitte

Silicon-photonics light source realized by III-V/Si grating-mirror laser

A III-V/Si vertical-cavity in-plane-emitting laser structure is suggested and numerically investigated. This hybrid laser consists of a distributed Bragg reflector, a III-V active region, and a high-index-contrast grating (HCG) connected to an in-plane output waveguide. The HCG and the output waveguide are made in the Si layer of a silicon-on-insulator wafer by using Si-electronics-compatible processing. The HCG works as a highly-reflective mirror for vertical resonance and at the same time routes light to the in-plane output waveguide. Numerical simulations show superior performance compared to existing silicon light sources

Influence of Pure Dephasing on Emission Spectra from Single Photon Sources

We investigate the light-matter interaction of a quantum dot with the electromagnetic field in a lossy microcavity and calculate emission spectra for non-zero detuning and dephasing. It is found that dephasing shifts the intensity of the emission peaks for non-zero detuning. We investigate the characteristics of this intensity shifting effect and offer it as an explanation for the non-vanishing emission peaks at the cavity frequency found in recent experimental work.Comment: Published version, minor change

Approaches to Studying: A Cross-Sectional Comparison of Occupational Therapy Students in Six Education Programs in Norway

Students’ approaches to studying have been associated with their academic performance. Although previous research suggests that the cultural and educational context may influence approaches to studying, few studies have investigated differences in study approaches across education programs. The aim of this study was to examine whether approaches to studying differed among occupational therapy students enrolled in six different educational programs in Norway. From a population of 308 students, 187 first-year occupational therapy students in six educational programs in Norway were recruited. The students provided their sociodemographic information and completed the Approaches and Study Skills Inventory for Students (ASSIST), and group differences were analyzed with Chi-square tests and one-way analyses of variance. Scores on the deep and surface approach scales did not differ significantly among the students in the six educational programs, while there was an overall difference in scores on the strategic approach scale. Group differences regarding the subscales were minor, and only a few of the pairwise differences reached statistical significance. Differences at the education program level appear not to be important for the interpretation of differences in study approaches among students