Neutron inelastic scattering investigation of the magnetic excitations in Cu_2Te_2O_5X_2 (X=Br, Cl)

Neutron inelastic scattering investigations have been performed on the spin tetrahedral system Cu_2Te_2O_5X_2 (X = Cl, Br). We report the observation of magnetic excitations with a dispersive component in both compounds, associated with the 3D incommensurate magnetic order that develops below $T^{Cl}_{N}$=18.2 K and $T^{Br}_{N}$=11.4 K. The excitation in Cu_2Te_2O_5Cl_2 softens as the temperature approaches $T^{Cl}_{N}$, leaving diffuse quasi-elastic scattering above the transition temperature. In the bromide, the excitations are present well above $T^{Br}_{N}$, which might be attributed to the presence of a degree of low dimensional correlations above $T^{Br}_{N}$ in this compound

Multi-Modal Human-Machine Communication for Instructing Robot Grasping Tasks

A major challenge for the realization of intelligent robots is to supply them with cognitive abilities in order to allow ordinary users to program them easily and intuitively. One way of such programming is teaching work tasks by interactive demonstration. To make this effective and convenient for the user, the machine must be capable to establish a common focus of attention and be able to use and integrate spoken instructions, visual perceptions, and non-verbal clues like gestural commands. We report progress in building a hybrid architecture that combines statistical methods, neural networks, and finite state machines into an integrated system for instructing grasping tasks by man-machine interaction. The system combines the GRAVIS-robot for visual attention and gestural instruction with an intelligent interface for speech recognition and linguistic interpretation, and an modality fusion module to allow multi-modal task-oriented man-machine communication with respect to dextrous robot manipulation of objects.Comment: 7 pages, 8 figure

Stress transfer and Quaternary faulting in the northern Alpine foreland

Within the SPP Mountain Building Processes in Four Dimensions (MB-4D) we studied postglacial and present seismic rupturing in the northern Alpine Foreland to better understand the impact and forces of mountain building. We started a seismological field experiment to densify the permanent monitoring networks and the AlpArray Seismic Network. The later was also supported as well as its predecessor UNIBRA (Hetényi et al., 2018; Schlömer et al., 2022). Our StressTransfer network consisted of five recording stations in the Upper Rhine Graben, five in the Molasse Basin and five around the Albstadt Shear Zone (Mader et al., 2021a). The latter are still operating due to the increased seismicity during the last years below the western Swabian Alb. We determined local minimum 1-D seismic velocity models to relocate known events in the study regions (Mader et al., 2021b). Waveform cross-correlation was done to detect hitherto unknown events and recover earthquake sequences around the Albstadt Shear Zone (Mader et al., subm.). To determine fault planes and rupture mechanisms we used relative event locations (hypoDD) and FOCMEC for fault plane solutions. For the Albstadt Shear Zone (ASZ), an NNE–SSW striking left-lateral strike-slip rupture zone, we determined a direction of the maximum horizontal stress (SHmax) of 140°–149°. Down to ca. 7–8 km depth, SHmax is bigger than SV (vertical stress); below this depth, SV is the main stress component. Beneath the shallow Hohenzollerngraben (ca. 2-3 km depth), which is nearly perpendicular to the ASZ, we found an NW-SE striking dextral strike-slip fault zone with very weak micro-seismicity in 11-15 km depth (Figure 1). This zone is possibly a reactivated old upper-crustal tectonic structure. At the interception of the ASZ and the NW-SE striking fault zone we observe NNW-SSE striking sinistral strike-slip and normal faulting micro-earthquakes which belong to a heterogeneous deformation zone with complex faulting. In Figure 1 we summarize our current model for the ASZ and its surroundings. The detection of many micro-earthquakes and the related active faults was only possible with the help of the additional temporal recording stations in the region and the studies of a PhD student (S.M.). We thank the DFG for funding our project and the State Earthquake Service Baden-Württemberg in Freiburg for providing data (Az. 4784//18_3303)

Reducing the linewidth of a diode laser below 30 Hz by stabilization to a reference cavity with finesse above 10^5

An extended cavity diode laser operating in the Littrow configuration emitting near 657 nm is stabilized via its injection current to a reference cavity with a finesse of more than 10^5 and a corresponding resonance linewidth of 14 kHz. The laser linewidth is reduced from a few MHz to a value below 30 Hz. The compact and robust setup appears ideal for a portable optical frequency standard using the Calcium intercombination line.Comment: 8 pages, 4 figures on 3 additional pages, corrected version, submitted to Optics Letter

Interactive Digital Music: Enhancing Listener Engagement with Commercial Music

Listeners have long been inspired to interact with music and create new representations of popular releases. Vinyl offered many opportunities to reappropriate chart music, from scratching and tempo manipulation to mixing multiple songs together. More recently, artists could engage their audience to interact with their music by offering mix-stems online for experimentation and sharing. With the extended processing power of mobile devices, the opportunities for interactive music are dramatically increasing. This paper presents research that demonstrates a novel approach to interactive digital music. The research looks at the emergent format of the album app and extends existing paradigms of interactive music playback. The novel album app designed in this research presents a new opportunity for listeners to engage with recorded content by allowing them to explore alternative takes, renditions of a given song in multiple genres, and by allowing direct interaction with embedded mix-stems. The resultant audio remains true to the artist and producer’s studio vision; it is user-influenced, but machine-controlled. The research is conducted in collaboration with artist Daisy and The Dark and was funded by the UK Arts and Humanities Research Council

Remote Entanglement between a Single Atom and a Bose-Einstein Condensate

Entanglement between stationary systems at remote locations is a key resource for quantum networks. We report on the experimental generation of remote entanglement between a single atom inside an optical cavity and a Bose-Einstein condensate (BEC). To produce this, a single photon is created in the atom-cavity system, thereby generating atom-photon entanglement. The photon is transported to the BEC and converted into a collective excitation in the BEC, thus establishing matter-matter entanglement. After a variable delay, this entanglement is converted into photon-photon entanglement. The matter-matter entanglement lifetime of 100 $\mu$s exceeds the photon duration by two orders of magnitude. The total fidelity of all concatenated operations is 95%. This hybrid system opens up promising perspectives in the field of quantum information

Are Drug Companies Living Up to Their Human Rights Responsibilities? The Merck Perspective

As one viewpoint of three in the PLoS Medicine Debate on whether drug companies are living up to their human rights responsibilities, Geralyn Ritter, Vice President of Global Health Policy and Corporate Social Responsibility at Merck & Co., argues that that multiple stakeholders could do more to help States deliver the right to health

Wigner flow reveals topological order in quantum phase space dynamics

The behaviour of classical mechanical systems is characterised by their phase portraits, the collections of their trajectories. Heisenberg's uncertainty principle precludes the existence of sharply defined trajectories, which is why traditionally only the time evolution of wave functions is studied in quantum dynamics. These studies are quite insensitive to the underlying structure of quantum phase space dynamics. We identify the flow that is the quantum analog of classical particle flow along phase portrait lines. It reveals hidden features of quantum dynamics and extra complexity. Being constrained by conserved flow winding numbers, it also reveals fundamental topological order in quantum dynamics that has so far gone unnoticed.Comment: 6 pages, 6 figure