Subjective burden of government-imposed Covid-19 restrictions in Switzerland: evidence from the 2022 LINK Covid-19 survey

BACKGROUND: While a large literature has quantified the health and economic impact of COVID-19, estimates on the subjective losses in quality of life due to government imposed restrictions remain scarce. METHODS: We conducted a nationally representative online survey in Switzerland in February 2022 to measure average self-reported quality of life with government restrictions. We used a discrete choice experiment to compute average willingness to pay for avoiding specific restrictions and time-trade-off questions to quantify the relative quality of life under restrictions. RESULTS: A total of 1299 Swiss residents completed the online survey between February 9th and 15th, 2022. On average, respondents valued life under severe restrictions at 39% of their usual life (estimated relative utility 0.39 [0.37, 0.42]). Willingness to pay for avoiding restrictions was lowest for masks (CHF 663 [319, 1007]), and highest for schools and daycares (CHF 4123 [3443, 4803]) as well as private parties (CHF 4520 [3811, 5229]). We estimate that between March 2020 and February 2022 a total of 5.7 Million QALYs were lost due to light, moderate and severe restrictions imposed by the governments. CONCLUSIONS: The quality of life losses due to government restrictions are substantial, particularly when it comes to the closure of schools and daycares, as well as the prohibition of private gatherings. Future policies should weigh these costs against the health benefits achievable with specific measures

Interfacing transitions of different alkali atoms and telecom bands using one narrowband photon pair source

Quantum information technology strongly relies on coupling of optical photons with narrowband quantum systems, such as quantum dots, color centers, and atomic systems. This coupling requires matching the optical wavelength and bandwidth to the desired system, which presents a considerable problem for most available sources of quantum light. Here we demonstrate coupling of alkali dipole transitions with a tunable source of photon pairs. Our source is based on spontaneous parametric down-conversion in a triply-resonant whispering-gallery mode resonator. For this, we have developed novel wavelength tuning mechanisms, which allow for a coarse tuning to either cesium or rubidium wavelength with subsequent continuous fine-tuning to the desired transition. As a demonstration of the functionality of the source, we performed a heralded single photon measurement of the atomic decay. We present a major advance in controlling the spontaneous down-conversion process, which makes our bright source of single photons now compatible with a plethora of narrow-band resonant systems.Comment: 8 pages, 5 figure

Off-resonant emission of photon pairs in nonlinear optical cavities

Cavity-assisted spontaneous parametric down-conversion (SPDC) and spontaneous four-wave mixing (SFWM) in nonlinear optical materials are practical and versatile methods to generate narrowband time-energy entangled photon pairs. Time- energy entangled photons with tailored spectro-temporal properties are particularly useful for efficient quantum optical interfaces. In this work we study the generation of photon pairs in cavity-assisted SPDC and SFWM for the general case of off-resonant conversion, namely, when the frequencies of the generated photons do not match the cavity resonances. Such a frequency mismatch in particular depends on temperature and requires an additional control in the experiment. First, we propose a generic model, for description of cavity-assisted SPDC and SFWM. We show that in both processes the mismatch reduces the generation rate of photons, distorts the spectrum and the auto-correlation function of the generated fields, as well as affects the photon generation dynamics. Second, we verify the results experimentally using parametric generation of photon pairs in a nonlinear whispering gallery mode resonator (WGMR) as an experimental platform with controlled frequency mismatch. Our work reveals the role of the frequency mismatch in the photon generation process and shows a way to control it. Obtained results constitute one more step in the direction of full control over the spectro-temporal properties of entangled photon pairs and the heralded generation of single-photon pulses with a tailored temporal mode

Hybrid-Entanglement in Continuous Variable Systems

Entanglement is one of the most fascinating features arising from quantum-mechanics and of great importance for quantum information science. Of particular interest are so-called hybrid-entangled states which have the intriguing property that they contain entanglement between different degrees of freedom (DOFs). However, most of the current continuous variable systems only exploit one DOF and therefore do not involve such highly complex states. We break this barrier and demonstrate that one can exploit squeezed cylindrically polarized optical modes to generate continuous variable states exhibiting entanglement between the spatial and polarization DOF. We show an experimental realization of these novel kind of states by quantum squeezing an azimuthally polarized mode with the help of a specially tailored photonic crystal fiber

DuPontTM OmneraTM LQMTM (DPX-SGE27) – Eine neue Generation flüssig formulierter Getreideherbizide

DuPontTM OmneraTM LQMTM (DPX-SGE27) (5 g/l Metsulfuron-methyl, 30 g/l Thifensulfuron-methyl, 135 g/l Fluroxypyr) stellt mit einer Aufwandmenge von 1 l/ha eine neue Lösung im Getreide gegen breitblättrige Unkräuter inkl. Klettenlabkraut (Galium aparine) dar. Dabei zeichnet sich DuPontTM OmneraTM LQMTM durch eine sehr gute Wirksamkeit, ein breites Wirkungsspektrum, ein breites Anwendungsfenster (BBCH 20 – 39 im Wintergetreide, BBCH 12 – 39 im Sommergetreide) und eine hohe Kulturverträglichkeit aus. DuPontTM OmneraTM LQMTM ist als Dispersion in Öl formuliert. Mehrjährige Versuche belegen die Wirksamkeit von DuPontTM OmneraTM LQMTM z.B. gegen Echte Kamille (Matricaria chamomilla), Ausfallraps (Brassica napus), Vogelmiere (Stellaria media), aber auch gegen Problemunkräuter wie z.B. Windenknöterich (Polygonum convolvulus) und vor allem gegen Klettenlabkraut. DuPontTM OmneraTM LQMTM (DPX-SGE27) – A new generation of liquid formulated cereal herbicidesDuPontTM OmneraTM LQMTM (DPX-SGE27) (5 g/l metsulfuron-methyl, 30 g/l thifensulfuron-methyl, 135 g/l fluroxypyr) represents with an application rate of 1 l/ha a new “herbicide” solution in cereals. DuPontTM OmneraTM LQMTM is characterized by a very good efficacy, a broad weed spectrum, a broad application window (BBCH 20 – 39 in winter cereals; BBCH 12 – 39 in spring cereals) and a very good crop safety. DuPontTM OmneraTM LQMTM is formulated as oil dispersion.Several years of field trials demonstrate the efficacy of DuPontTM OmneraTM LQMTM against mayweed (Matricaria chamomilla), oilseed rape (Brassica napus), common chickweed (Stellaria media), but also against difficult weeds like wild buckwheat (Polygonum convolvulus) and especially against catchweed bedstraw (Galium aparine)

Proton inelastic scattering to continuum studied with antisymmetrized molecular dynamics

Intermediate energy (p,p$'$x) reaction is studied with antisymmetrized molecular dynamics (AMD) in the cases of $^{58}$Ni target with $E_p = 120$ MeV and $^{12}$C target with $E_p =$ 200 and 90 MeV. Angular distributions for various $E_{p'}$ energies are shown to be reproduced well without any adjustable parameter, which shows the reliability and usefulness of AMD in describing light-ion reactions. Detailed analyses of the calculations are made in the case of $^{58}$Ni target and following results are obtained: Two-step contributions are found to be dominant in some large angle region and to be indispensable for the reproduction of data. Furthermore the reproduction of data in the large angle region \theta \agt 120^\circ for $E_{p'}$ = 100 MeV is shown to be due to three-step contributions. Angular distributions for E_{p'} \agt 40 MeV are found to be insensitive to the choice of different in-medium nucleon-nucleon cross sections $\sigma_{NN}$ and the reason of this insensitivity is discussed in detail. On the other hand, the total reaction cross section and the cross section of evaporated protons are found to be sensitive to $\sigma_{NN}$. In the course of the analyses of the calculations, comparison is made with the distorted wave approach.Comment: 16 pages, 7 Postscript figure

Wavelet signatures of KK-splitting of the Isoscalar Giant Quadrupole Resonance in deformed nuclei from high-resolution (p,p′') scattering off 146,148,150^{146,148,150}Nd

The phenomenon of fine structure of the Isoscalar Giant Quadrupole Resonance (ISGQR) has been studied with high energy-resolution proton inelastic scattering at iThemba LABS in the chain of stable even-mass Nd isotopes covering the transition from spherical to deformed ground states. A wavelet analysis of the background-subtracted spectra in the deformed 146,148,150Nd isotopes reveals characteristic scales in correspondence with scales obtained from a Skyrme RPA calculation using the SVmas10 parameterization. A semblance analysis shows that these scales arise from the energy shift between the main fragments of the K = 0, 1 and K = 2 components.Comment: 7 pages, 6 figure

Studies of the Giant Dipole Resonance in 27^{27}Al, 40^{40}Ca, 56^{56}Fe, 58^{58}Ni and 208^{208}Pb with high energy-resolution inelastic proton scattering under 0∘^\circ

A survey of the fine structure of the Isovector Giant Dipole Resonance (IVGDR) was performed, using the recently commissioned zero-degree facility of the K600 magnetic spectrometer at iThemba LABS. Inelastic proton scattering at an incident energy of 200 MeV was measured on $^{27}$Al, $^{40}$Ca, $^{56}$Fe, $^{58}$Ni and $^{208}$Pb. A high energy resolution ($\rm{\Delta}\it{E} \simeq$ 40 keV FWHM) could be achieved after utilising faint-beam and dispersion-matching techniques. Considerable fine structure is observed in the energy region of the IVGDR and characteristic energy scales are extracted from the experimental data by means of a wavelet analysis. The comparison with Quasiparticle-Phonon Model (QPM) calculations provides insight into the relevance of different giant resonance decay mechanisms. Photoabsorption cross sections derived from the data assuming dominance of relativistic Coulomb excitation are in fair agreement with previous work using real photons.Comment: 15 pages, 15 figure

Cross-polarized photon-pair generation and bi-chromatically pumped optical parametric oscillation on a chip

Nonlinear optical processes are one of the most important tools in modern optics with a broad spectrum of applications in, for example, frequency conversion, spectroscopy, signal processing and quantum optics. For practical and ultimately widespread implementation, on-chip devices compatible with electronic integrated circuit technology offer great advantages in terms of low cost, small footprint, high performance and low energy consumption. While many on-chip key components have been realized, to date polarization has not been fully exploited as a degree of freedom for integrated nonlinear devices. In particular, frequency conversion based on orthogonally polarized beams has not yet been demonstrated on chip. Here we show frequency mixing between orthogonal polarization modes in a compact integrated microring resonator and demonstrate a bi-chromatically pumped optical parametric oscillator. Operating the device above and below threshold, we directly generate orthogonally polarized beams, as well as photon pairs, respectively, that can find applications, for example, in optical communication and quantum optics

Study of the nucleon-induced preequilibrium reactions in terms of the Quantum Molecular Dynamics

The preequilibrium (nucleon-in, nucleon-out) angular distributions of $^{27}$Al, $^{58}$Ni and $^{90}$Zr have been analyzed in the energy region from 90 to 200 MeV in terms of the Quantum Moleculear Dynamics (QMD) theory. First, we show that the present approach can reproduce the measured (p,xp') and (p,xn) angular distributions leading to continuous final states without adjusing any parameters. Second, we show the results of the detailed study of the preequilibrium reaction processes; the step-wise contribution to the angular distribution, comparison with the quantum-mechanical Feshbach-Kerman-Koonin theory, the effects of momentum distribution and surface refraction/reflection to the quasifree scattering. Finally, the present method was used to assess the importance of multiple preequilibrium particle emission as a function of projectile energy up to 1 GeV.Comment: 22pages, Revex is used, 10 Postscript figures are available by request from [email protected]