56 research outputs found
Topologically-protected single-photon sources with topological slow light photonic crystal waveguides
Slow light waveguides are advantageous for implementing high-performance
single-photon sources required for scalable operation of integrated quantum
photonic circuits (IQPCs), though such waveguides are known to suffer from
propagation loss due to backscattering. A way to overcome the drawback is to
use topological photonics, in which robust waveguiding in
topologically-protected optical modes has recently been demonstrated. Here, we
report single-photon sources using single quantum dots (QDs) embedded in
topological slow light waveguides based on valley photonic crystals. We observe
Purcell-enhanced single-photon emission from a QD into a topological slow light
mode with a group index over 20 and its robust propagation even under the
presence of sharp bends. These results pave the way for the realization of
robust and high-performance single-photon sources indispensable for IQPCs
Higher media multi-tasking activity is associated with smaller gray-matter density in the anterior cingulate cortex
Media multitasking, or the concurrent consumption of multiple media forms, is increasingly prevalent in today’s society and has been associated with negative psychosocial and cognitive impacts. Individuals who engage in heavier media-multitasking are found to perform worse on cognitive control tasks and exhibit more socio-emotional difficulties. However, the neural processes associated with media multi-tasking remain unexplored. The present study investigated relationships between media multitasking activity and brain structure. Research has demonstrated that brain structure can be altered upon prolonged exposure to novel environments and experience. Thus, we expected differential engagements in media multitasking to correlate with brain structure variability. This was confirmed via Voxel-Based Morphometry (VBM) analyses: Individuals with higher Media Multitasking Index (MMI) scores had smaller gray matter density in the anterior cingulate cortex (ACC). Functional connectivity between this ACC region and the precuneus was negatively associated with MMI. Our findings suggest a possible structural correlate for the observed decreased cognitive control performance and socio-emotional regulation in heavy media-multitaskers. While the cross-sectional nature of our study does not allow us to specify the direction of causality, our results brought to light novel associations between individual media multitasking behaviors and ACC structure differences
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