ABSTRACT
Deterministic sources of multiphoton entanglement are highly attractive for quantum information processing but are challenging to realize experimentally. In this Letter, we demonstrate a route toward a scaleable source of time-bin encoded Greenberger-Horne-Zeilinger and linear cluster states from a solid-state quantum dot embedded in a nanophotonic crystal waveguide. By utilizing a self-stabilizing double-pass interferometer, we measure a spin-photon Bell state with (67.8±0.4)% fidelity and devise steps for significant further improvements. By employing strict resonant excitation, we demonstrate a photon indistinguishability of (95.7±0.8)%, which is conducive to fusion of multiple cluster states for scaling up the technology and producing more general graph states.
ABSTRACT
BACKGROUND: The efficacy of body-oriented yoga in the treatment of mental disorders has been investigated in numerous studies. This article is a systematic review and meta-analysis of the relevant publications. METHODS: All studies in which the efficacy of hatha-yoga, i.e., body-oriented yoga with asanas and pranayama, was studied in adult patients suffering from a mental disorder (as diagnosed by ICD or DSM criteria) were included in the analysis. The primary endpoint was disorder-specific symptom severity. The publications were identified by a systematic search in the PubMed, Web of Science, PsycINFO and ProQuest databases, supplemented by a search with the Google Scholar search engine and a manual search in the reference lists of meta-analyses and primary studies, as well as in specialized journals. RESULTS: 25 studies with a total of 1339 patients were included in the analysis. A large and significant effect of yoga was seen with respect to the primary endpoint (symptom severity) (Hedges' g = 0.91; 95% confidence interval [0.55; 1.28]; number needed to treat [NNT]: 2.03), with substantial heterogeneity (I2 = 69.8%) compared to untreated control groups. Small but significant effects of yoga were also seen in comparison with attention control (g = 0.39; [0.04; 0.73]; NNT: 4.55) and physical exercise (g = 0.30; [0.01; 0.59]; NNT: 5.75); no difference in efficacy was found between yoga and standard psychotherapy (g = 0.08; [-0.24; 0,40]; NNT: 21.89). In view of the relatively high risk of bias, these findings should be interpreted with caution. CONCLUSION: Body-oriented yoga with asanas and pranayama as central components is a promising complementary treatment for mental disorders and should be investigated in further high-quality studies.
