Unconventional monetary policy and inflation expectations in the Euro area. CEPS Working Document No 2020/01, January 2020

With the ECB's policy rate having reached the zero lower bound, traditional monetary policy tools became ineffective and the ECB was forced to adopt a set of unconventional monetary policy (UMP) measures. This paper examines the effects of the ECB's UMP on inflation expectations in the Euro area as inflation expectations play a key role for achieving the inflation target of below, but close to 2%. Quantifying the impact of UMP is not straightforward, as standard empirical tools such as VAR cannot be applied. Hence, we use the Qual VAR approach pioneered by Dueker (2005) to overcome this problem. We indeed find that UMP leads to a rise in inflation expectations in the short run but that this effect appears to evaporate in the medium term. Our results put some doubt on the common claim that UMP has consistently contributed to a re-anchoring and a stabilisation of inflation expectations at the zero lower bound. Nevertheless, they indicate a rise in mediumterm real GDP growth triggered by UMP

A spintronic source of circularly polarized single photons

We present a spintronic single photon source which emits circularly polarized light, where the helicity is determined by an applied magnetic field. Photons are emitted from an InGaAs quantum dot inside an electrically operated spin light-emitting diode, which comprises the diluted magnetic semiconductor ZnMnSe. The circular polarization degree of the emitted light is high, reaching 83% at an applied magnetic field of 2T and 96% at 6 T. Autocorrelation traces recorded in pulsed operation mode prove the emitted light to be antibunched. The two circular polarization states could be used for representing quantum states |0> and |1> in quantum cryptography implementations

Growth and reproduction of the alpine grasshopper Miramella alpina feeding on CO2-enriched dwarf shrubs at treeline

The consequences for plant-insect interactions of atmospheric changes in alpine ecosystems are not well understood. Here, we tested the effects of elevated CO2 on leaf quality in two dwarf shrub species (Vaccinium myrtillus and V. uliginosum) and the response of the alpine grasshopper (Miramella alpina) feeding on these plants in a field experiment at the alpine treeline (2,180m a.s.l.) in Davos, Switzerland. Relative growth rates (RGR) of M. alpina nymphs were lower when they were feeding on V. myrtillus compared to V. uliginosum, and were affected by elevated CO2 depending on plant species and nymph developmental stage. Changes in RGR correlated with CO2-induced changes in leaf water, nitrogen, and starch concentrations. Elevated CO2 resulted in reduced female adult weight irrespective of plant species, and prolonged development time on V. uliginosum only, but there were no significant differences in nymphal mortality. Newly molted adults of M. alpina produced lighter eggs and less secretion (serving as egg protection) under elevated CO2. When grasshoppers had a choice among four different plant species grown either under ambient or elevated CO2, V. myrtillus and V. uliginosum consumption increased under elevated CO2 in females while it decreased in males compared to ambient CO2-grown leaves. Our findings suggest that rising atmospheric CO2 distinctly affects leaf chemistry in two important dwarf shrub species at the alpine treeline, leading to changes in feeding behavior, growth, and reproduction of the most important insect herbivore in this system. Changes in plant-grasshopper interactions might have significant long-term impacts on herbivore pressure, community dynamics and ecosystem stability in the alpine treeline ecoton

Vortex states in patterned exchange biased NiO/Ni samples

We investigated the magnetization reversal of arrays of exchange biased NiO/Ni squares with superconducting quantum interference device magnetometry and micromagnetic simulations. The edges of the squares were 0.5, 1.5, and 3.0 $\mu$m long. The NiO/Ni structures exhibit vortexlike hysteresis loops and micromagnetic calculations show that this feature is due to several vortices nucleating in the islands. Furthermore, for the arrays with squares of 1.5 $\mu$m edge length, the sign of the exchange bias field changes, as compared to the same continuous NiO/Ni layer. We attribute the vortex nucleation and the change of the exchange bias field to the interplay between shape and unidirectional anisotropy.Comment: 6 pages, 7 figure

Die Kybernetik als Theoriegerüst der Systemischen Beratung - Darstellung und Kritik

Die systemische Beratung beruft sich auf ein breites Theoriefundament. Exemplarisch für dieses Theoriegerüst werden in diesem Beitrag die Kybernetik 1. und 2. Ordnung dargestellt und geprüft, inwiefern systemische Berater diese Theorien umsetzen und inwieweit sie theoriegeleitet arbeiten können. Es wird diskutiert, ob eine radikal konstruktivistische Haltung in einem Beratungssetting gewinnbringend ist und welche Konsequenzen ein theoriegeleitetes Arbeiten im Sinne der Kybernetik 2. Ordnung mit sich bringen würde

Magnetoresistance in Co-hBN-NiFe tunnel junctions enhanced by resonant tunneling through single defects in ultrathin hBN barriers

Hexagonal boron nitride (hBN) is a prototypical high-quality two-dimensional insulator and an ideal material to study tunneling phenomena, as it can be easily integrated in vertical van der Waals devices. For spintronic devices, its potential has been demonstrated both for efficient spin injection in lateral spin valves and as a barrier in magnetic tunnel junctions (MTJs). Here we reveal the effect of point defects inevitably present in mechanically exfoliated hBN on the tunnel magnetoresistance of Co-hBN-NiFe MTJs. We observe a clear enhancement of both the conductance and magnetoresistance of the junction at well-defined bias voltages, indicating resonant tunneling through magnetic (spin-polarized) defect states. The spin polarization of the defect states is attributed to exchange coupling of a paramagnetic impurity in the few-atomic-layer thick hBN to the ferromagnetic electrodes. This is confirmed by excellent agreement with theoretical modelling. Our findings should be taken into account in analyzing tunneling processes in hBN-based magnetic devices. More generally, our study shows the potential of using atomically thin hBN barriers with defects to engineer the magnetoresistance of MTJs and to achieve spin filtering, opening the door towards exploiting the spin degree of freedom in current studies of point defects as quantum emitters

Temperature measurements and thermal gradient estimates on the slope and shelf edge region of the Beaufort Sea, Canada

In situ temperature measurements were conducted at 63 gravity-core stations during the 2013 expedition with the CCGS Sir Wilfrid Laurier in the Canadian Beaufort Sea. Outriggers attached to the outside of the gravity core-barrel were used to mount portable miniature temperature loggers (MTL) for down-core in situ temperature measurements. Several sub-regions were investigated during the expedition including two shelf-slope crossings, three mud volcano-type expulsion features, as well as two canyon sites. The last site visited was at the Gary Knolls, just east of the Mackenzie Trough at water depths of less than 100 m. Overall, temperature data obtained from the MTLs were of high quality at most stations and the data acquisition technique was proven to be robust and easy to adapt in the Arctic. However, depth determination for each logger position remains the largest challenge as no additional pressure sensor was used with the MTLs. Instead, depths were estimated based on the apparent core penetration and the geometry of the outriggers. The most significant result from this work is the discovery of the very large apparent geothermal gradients associated with the two expulsion features (EF) Coke Cap and the mud volcano at 420 m water depth. Temperatures measured within the top 2.5 meter below seafloor suggest geothermal gradients of up to 2.94ºC/m (Station 96, 420m EF) and 1.37 ºC/m (Station 58, Coke Cap EF). Away from the centre of the EFs, thermal gradients decrease to values of 0.5ºC/m for Station 99 at the 420 m EF, and 0.92ºC/m at Station 21 at the Coke Cap EF. Temperature data across the slope-shelf transect and the two transects across the canyon heads did not reveal considerable geothermal gradients, but show a water-depth dependent trend in temperature. From deep to shallow water, temperature appear to decrease until the most negative temperature values are found on the shelf itself at water depths of ~100 m (-1.2 to -1.4ºC). Overall, data from the top 1.0 to 1.5 meter below seafloor are likely affected by seasonal variations in the water column temperature and may not be used to define geothermal gradients. With an optimal full penetration of the core barrel, the deepest temperature data are from ~2.3 mbsf, which limits the accuracy of the estimated geothermal gradients as only few data points (2 - 4) can be used in the calculations

Supervision/Coaching in der Lehrer*innenbildung: Einblicke in die Inanspruchnahme aus psychometrischer und hermeneutisch-rekonstruktiver Perspektive

Die Inanspruchnahme von Supervsision/Coaching dient in vielen Berufsfeldern als Möglichkeit der Professionalierung, z.B. auch in der Lehrer*innenausbildung. In der vorliegen Studie wird die Intention von Junglehrer*innen unstersucht, in ihrem Berufsleben Supervision/Coaching in Anspruch zu nehmen. Basierend auf der Theorie des geplanten Verhaltens (Theory of planned Bevaviour) wurde ein reliaber und valider Fragebogen zu dieser Thematik entwickelt, der von 132 Leher*innen berbeitet wurde. Es zeigte sich, dass die Intention Supervison/Coaching in Anspruch zu nehmen in erster Linie von den Einstellungen und der (beruflichen) sozialen Norm der Proband*innen abhing. Die empfundene soziale Norm der Stichprobe war gering ausgeprägt, hingegen waren die Einstellungen zur Supervision/zum Coachimg der Stichprobe positiv. Trotzdem war die Bereitschaft, an einer Supervison/einem Coaching teilzunehmen nur im durchschnittlichen Bereich verortet. Die statistischen Befunde der vorliegenden Untersuchung werden vor dem Hintergrund einer hermeneutisch-rekonstruktiven Perspektive diskutiert, insbesondere die beobachtete „Attitude-Intention-Gap“. Zudem wird das Verhältnis Supervison/Coaching und Schule perspektivisch beleuchtet.The use of supervision/coaching serves in many professional fields as an opportunity for professionalisation, e.g. also in teacher training. In the present study, the intention of young teachers to make use of supervision/coaching in their professional life is explored. Based on the theory of planned behaviour (Theorie des geplanten Verhaltens) a reliable and valid questionnaire on this topic was developed, which was worked on by 132 teachers. It turned out that the intention to receive supervision/coaching depended primarily on the attitudes and the (professional) social norm of the participants. The perceived social norm of the sample was low, but the attitudes towards supervision/coaching of the sample were positive. Nevertheless, the willingness to participate in supervision/coaching was only within the average range. The statistical findings of the present study will be discussed in the context of a hermeneutic-reconstructive perspective, especially the observed "attitude-intention-gap". Furthermore, the relationship between supervision/coaching and school will be examined from a perspectiv