Realization of all-optical vortex switching in exciton-polariton condensates

This work was supported by the Deutsche Forschungsgemeinschaft (DFG) through the collaborative research center TRR142 (grant No. 231447078, project A04) and Heisenberg program (grant No. 270619725) and by the Paderborn Center for Parallel Computing, PC2. X.M. further ackowledges support from the NSFC (No. 11804064). The Würzburg group acknowledges support by the state of Bavaria.Vortices are topological objects representing the circular motion of a fluid. With their additional degree of freedom, the 'vorticity', they have been widely investigated in many physical systems and different materials for fundamental interest and for applications in data storage and information processing. Vortices have also been observed in non-equilibrium exciton-polariton condensates in planar semiconductor microcavities. There they appear spontaneously or can be created and pinned in space using ring-shaped optical excitation profiles. However, using the vortex state for information processing not only requires creation of a vortex but also efficient control over the vortex after its creation. Here we demonstrate a simple approach to control and switch a localized polariton vortex between opposite states. In our scheme, both the optical control of vorticity and its detection through the orbital angular momentum of the emitted light are implemented in a robust and practical manner.Publisher PDFPeer reviewe

Der Kopfschmerzpatient auf der Notfallstation - wie weiter?

Patienten mit Kopfschmerzen auf dem Notfall sind häufig und trotzdem nicht trivial in der Abklärung und Behandlung. Man unterscheidet primäre, das heisst ohne fassbare Auslöser auftretende, von sekundären Kopfschmerzen, bei denen eine Ursache festzustellen ist, wie beispielsweise eine andere Erkrankung, Laborveränderungen oder die Einnahme bestimmter Medikamente

Sprachliche Verfestigung und sprachlich Verfestigtes.: Einleitung

The present special issue of Linguistik Online is dedicated to theoretical and methodological approaches to formulaic language use from a pragmatic perspective. Following the assumption that language use is thoroughly shaped by routines and prefabricated patterns, formulaic language plays a central role in recent theoretical and empirical approaches to language use like construction grammar or corpus pragmatics. Within the field of phraseology, pragmatic approaches have become prevalent, too, be it by corpus linguistic foundations or by a functional perspective on phrasemes in different communicative domains. Based on case studies from various fields like language acquisition, cultural linguistics or colonial studies, the papers of this special issue discuss the role of formulaicity on the different levels of language use. They demonstrate which concepts and empirical methods are suitable to capture the pragmatic aspects of formulaic language use

Baseline characteristics and comparability of older multimorbid patients with polypharmacy and general practitioners participating in a randomized controlled primary care trial.

OBJECTIVES Recruiting general practitioners (GPs) and their multimorbid older patients for trials is challenging for multiple reasons (e.g., high workload, limited mobility). The comparability of study participants is important for interpreting study findings. This manuscript describes the baseline characteristics of GPs and patients participating in the 'Optimizing PharmacoTherapy in older multimorbid adults In primary CAre' (OPTICA) trial, a study of optimization of pharmacotherapy for multimorbid older adults. The overall aim of this study was to determine if the GPs and patients participating in the OPTICA trial are comparable to the real-world population in Swiss primary care. DESIGN Analysis of baseline data from GPs and patients in the OPTICA trial and a reference cohort from the FIRE ('Family medicine ICPC Research using Electronic medical records') project. SETTING Primary care, Switzerland. PARTICIPANTS Three hundred twenty-three multimorbid (≥ 3 chronic conditions) patients with polypharmacy (≥ 5 regular medications) aged ≥ 65 years and 43 GPs recruited for the OPTICA trial were compared to 22,907 older multimorbid patients with polypharmacy and 227 GPs from the FIRE database. METHODS We compared the characteristics of GPs and patients participating in the OPTICA trial with other GPs and other older multimorbid adults with polypharmacy in the FIRE database. We described the baseline willingness to have medications deprescribed of the patients participating in the OPTICA trial using the revised Patients' Attitudes Towards Deprescribing (rPATD) questionnaire. RESULTS The GPs in the FIRE project and OPTICA were similar in terms of sociodemographic characteristics and their work as a GP (e.g. aged in their fifties, ≥ 10 years of experience, ≥ 60% are self-employed, ≥ 80% work in a group practice). The median age of patients in the OPTICA trial was 77 years and 45% of trial participants were women. Patients participating in the OPTICA trial and patients in the FIRE database were comparable in terms of age, certain clinical characteristics (e.g. systolic blood pressure, body mass index) and health services use (e.g. selected lab and vital data measurements). More than 80% of older multimorbid patients reported to be willing to stop ≥ 1 of their medications if their doctor said that this would be possible. CONCLUSION The characteristics of patients and GPs recruited into the OPTICA trial are relatively comparable to characteristics of a real-world Swiss population, which indicates that recruiting a generalizable patient sample is possible in the primary care setting. Multimorbid patients in the OPTICA trial reported a high willingness to have medications deprescribed. TRIAL REGISTRATION Clinicaltrials.gov ( NCT03724539 ), KOFAM (Swiss national portal) ( SNCTP000003060 ), Universal Trial Number (U1111-1226-8013)

Vortex circulation patterns in planar microdisk arrays

We report a magnetic X-ray microscopy study of the pattern formation of circulation in arrays of magnetic vortices ordered in a hexagonal and a honeycomb lattice. In the honeycomb lattice, we observe at remanence an ordered phase of alternating circulations, whereas in the hexagonal lattice, small regions of alternating lines form. A variation in the edge-to-edge distance shows that the size of those regions scales with the magnetostatic interaction. Micromagnetic simulations reveal that the patterns result from the formation of flux closure states during the nucleation process

Optimising prescribing in older adults with multimorbidity and polypharmacy in primary care (OPTICA): cluster randomised clinical trial.

OBJECTIVE To study the effects of a primary care medication review intervention centred around an electronic clinical decision support system (eCDSS) on appropriateness of medication and the number of prescribing omissions in older adults with multimorbidity and polypharmacy compared with a discussion about medication in line with usual care. DESIGN Cluster randomised clinical trial. SETTING Swiss primary care, between December 2018 and February 2021. PARTICIPANTS Eligible patients were ≥65 years of age with three or more chronic conditions and five or more long term medications. INTERVENTION The intervention to optimise pharmacotherapy centred around an eCDSS was conducted by general practitioners, followed by shared decision making between general practitioners and patients, and was compared with a discussion about medication in line with usual care between patients and general practitioners. MAIN OUTCOME MEASURES Primary outcomes were improvement in the Medication Appropriateness Index (MAI) and the Assessment of Underutilisation (AOU) at 12 months. Secondary outcomes included number of medications, falls, fractures, and quality of life. RESULTS In 43 general practitioner clusters, 323 patients were recruited (median age 77 (interquartile range 73-83) years; 45% (n=146) women). Twenty one general practitioners with 160 patients were assigned to the intervention group and 22 general practitioners with 163 patients to the control group. On average, one recommendation to stop or start a medication was reported to be implemented per patient. At 12 months, the results of the intention-to-treat analysis of the improvement in appropriateness of medication (odds ratio 1.05, 95% confidence interval 0.59 to 1.87) and the number of prescribing omissions (0.90, 0.41 to 1.96) were inconclusive. The same was the case for the per protocol analysis. No clear evidence was found for a difference in safety outcomes at the 12 month follow-up, but fewer safety events were reported in the intervention group than in the control group at six and 12 months. CONCLUSIONS In this randomised trial of general practitioners and older adults, the results were inconclusive as to whether the medication review intervention centred around the use of an eCDSS led to an improvement in appropriateness of medication or a reduction in prescribing omissions at 12 months compared with a discussion about medication in line with usual care. Nevertheless, the intervention could be safely delivered without causing any harm to patients. TRIAL REGISTRATION NCT03724539Clinicaltrials.gov NCT03724539

Optimising prescribing in older adults with multimorbidity and polypharmacy in primary care (OPTICA): cluster randomised clinical trial

OBJECTIVE To study the effects of a primary care medication review intervention centred around an electronic clinical decision support system (eCDSS) on appropriateness of medication and the number of prescribing omissions in older adults with multimorbidity and polypharmacy compared with a discussion about medication in line with usual care. DESIGN Cluster randomised clinical trial. SETTING Swiss primary care, between December 2018 and February 2021. PARTICIPANTS Eligible patients were ≥65 years of age with three or more chronic conditions and five or more long term medications. INTERVENTION The intervention to optimise pharmacotherapy centred around an eCDSS was conducted by general practitioners, followed by shared decision making between general practitioners and patients, and was compared with a discussion about medication in line with usual care between patients and general practitioners. MAIN OUTCOME MEASURES Primary outcomes were improvement in the Medication Appropriateness Index (MAI) and the Assessment of Underutilisation (AOU) at 12 months. Secondary outcomes included number of medications, falls, fractures, and quality of life. RESULTS In 43 general practitioner clusters, 323 patients were recruited (median age 77 (interquartile range 73-83) years; 45% (n=146) women). Twenty one general practitioners with 160 patients were assigned to the intervention group and 22 general practitioners with 163 patients to the control group. On average, one recommendation to stop or start a medication was reported to be implemented per patient. At 12 months, the results of the intention-to-treat analysis of the improvement in appropriateness of medication (odds ratio 1.05, 95% confidence interval 0.59 to 1.87) and the number of prescribing omissions (0.90, 0.41 to 1.96) were inconclusive. The same was the case for the per protocol analysis. No clear evidence was found for a difference in safety outcomes at the 12 month follow-up, but fewer safety events were reported in the intervention group than in the control group at six and 12 months. CONCLUSIONS In this randomised trial of general practitioners and older adults, the results were inconclusive as to whether the medication review intervention centred around the use of an eCDSS led to an improvement in appropriateness of medication or a reduction in prescribing omissions at 12 months compared with a discussion about medication in line with usual care. Nevertheless, the intervention could be safely delivered without causing any harm to patients. TRIAL REGISTRATION NCT03724539Clinicaltrials.gov NCT03724539

Accurate photon echo timing by optical freezing of exciton dephasing and rephasing in quantum dots

Semiconductor quantum dots are excellent candidates for ultrafast coherent manipulation of qubits by laser pulses on picosecond timescales or even faster. In inhomogeneous ensembles a macroscopic optical polarization decays rapidly due to dephasing, which, however, is reversible in photon echoes carrying complete information about the coherent ensemble dynamics. Control of the echo emission time is mandatory for applications. Here, we propose a concept to reach this goal. In a two-pulse photon echo sequence, we apply an additional resonant control pulse with multiple of 2π area. Depending on its arrival time, the control slows down dephasing or rephasing of the exciton ensemble during its action. We demonstrate for self-assembled (In,Ga)As quantum dots that the photon echo emission time can be retarded or advanced by up to 5 ps relative to its nominal appearance time without control. This versatile protocol may be used to obtain significantly longer temporal shifts for suitably tailored control pulses