[2-(4-Methyl­piperazin-1-ylmeth­yl)phen­yl]diphenyl­phosphane

In the title compound, C24H27N2P, the P atom is bonded to three C atoms in a trigonal–pyramidal geometry. The overall Ψ-trigonal-bipyramidal coordination of the P atom is established when the contribution of the electron lone pair and of the N—P donor–acceptor distance of 3.051 (3)Å are considered. The 4-methyl­piperazinyl ring adopts a chair conformation. Intra- and inter­molecular C—H⋯π hydrogen bonding leads to the consolidation of the structure

Polaron formation in the presence of Rashba spin-orbit coupling: implications for spintronics

We study the effects of the Rashba spin-orbit coupling on the polaron formation, using a suitable generalization of the Momentum Average approximation. Contrary to previous investigations of this problem, we find that the spin-orbit interaction decreases the effective electron-phonon coupling. It is thus possible to lower the effective mass of the polaron by increasing the spin-orbit coupling. We also show that when the spin-orbit coupling is large as compared to the phonon energy, the polaron retains only one of the spin polarized bands in its coherent spectrum. This has major implications for the propagation of spin-polarized currents in such materials, and thus for spintronic applications.Comment: 4 pages, 3 figure

Do I smell coffee? The tale of a 360º Mulsemedia experience

One of the main challenges in current multimedia networking environments is to find solutions to help accommodate the next generation of mobile application classes with stringent Quality of Service (QoS) requirements whilst enabling Quality of Experience (QoE) provisioning for users. One such application class, featured in this paper, is 360º mulsemedia—multiple sensorial media—which enriches 360º video by adding sensory effects that stimulate human senses beyond those of sight and hearing, such as the tactile and olfactory ones. In this paper, we present a conceptual framework for 360º mulsemedia delivery and a 360º mulsemedia-based prototype that enables users to experience 360º mulsemedia content. User evaluations revealed that higher video resolutions do not necessarily lead to the highest QoE levels in our experimental setup. Therefore, bandwidth savings can be leveraged with no detrimental impact on QoE

360° Mulsemedia: a way to improve subjective QoE in 360° videos

Previous research has shown that adding multisensory media-mulsemedia-to traditional audiovisual content has a positive effect on user Quality of Experience (QoE). However, the QoE impact of employing mulsemedia in 360° videos has remained unexplored. Accordingly, in this paper, a QoE study for watching a 360° video-with and without multisensory effects-in a full free-viewpoint VR setting is presented. The parametric space we considered to influence the QoE consists of the encoding quality and the motion level of the transmitted media. To achieve our research aim, we propose a wearable VR system that provides multisensory enhancement of 360° videos. Then, we utilise its capabilities to systematically evaluate the effects of multisensory stimulation on perceived quality degradation for videos with different motion levels and encoding qualities. Our results make a strong case for the inclusion of multisensory effects in 360° videos, as they reveal that both user-perceived quality, as well as enjoyment, are significantly higher when mulsemedia (as opposed to traditional multimedia) is employed in this context. Moreover, these observations hold true independent of the underlying 360° video encoding quality-thus QoE can be significantly enhanced with a minimal impact on networking resources

The influence of human factors on 360∘ mulsemedia QoE

Quality of Experience (QoE) is indelibly linked to the human side of the multimedia experience. Surprisingly, however, there is a paucity of research which explores the impact that human factors has in determining QoE. Whilst this is true of multimedia, it is even more starkly so as far as mulsemedia - applications that involve media engaging three or more of human senses - is concerned. Hence, in the study reported in this paper, we focus on an exciting subset of mulsemedia applications - 360∘ mulsemedia - particularly important given that the upcoming 5G technology is foreseen to be a key enabler for the proliferation of immersive Virtual Reality (VR) applications. Accordingly, we study the impact that human factors such as gender, age, prior computing experience, and smell sensitivity have on 360∘ mulsemedia QoE. Results showed insight into the potential of 360∘ mulsemedia to inspire and to enrich experiences for Generation Z - a generation empowered by rapidly advancing technology. Patterns of prior media usage and smell sensitivity play also an important role in influencing the QoE evaluation - users who have a preference for dynamic videos enjoy and find realistic the 360∘ mulsemedia experiences

Multisensory 360 videos under varying resolution levels enhance presence

Omnidirectional videos have become a leading multimedia format for Virtual Reality applications. While live 360◦ videos offer a unique immersive experience, streaming of omnidirectional content at high resolutions is not always feasible in bandwidth-limited networks. While in the case of flat videos, scaling to lower resolutions works well, 360◦ video quality is seriously degraded because of the viewing distances involved in head-mounted displays. Hence, in this paper, we investigate first how quality degradation impacts the sense of presence in immersive Virtual Reality applications. Then, we are pushing the boundaries of 360◦ technology through the enhancement with multisensory stimuli. 48 participants experimented both 360◦ scenarios (with and without multisensory content), while they were divided randomly between four conditions characterised by different encoding qualities (HD, FullHD, 2.5K, 4K). The results showed that presence is not mediated by streaming at a higher bitrate. The trend we identified revealed however that presence is positively and significantly impacted by the enhancement with multisensory content. This shows that multisensory technology is crucial in creating more immersive experiences

The Meissner effect in a strongly underdoped cuprate above its critical temperature

The Meissner effect and the associated perfect "bulk" diamagnetism together with zero resistance and gap opening are characteristic features of the superconducting state. In the pseudogap state of cuprates unusual diamagnetic signals as well as anomalous proximity effects have been detected but a Meissner effect has never been observed. Here we have probed the local diamagnetic response in the normal state of an underdoped La1.94Sr0.06CuO4 layer (up to 46 nm thick, critical temperature Tc' < 5 K) which was brought into close contact with two nearly optimally doped La1.84Sr0.16CuO4 layers (Tc \approx 32 K). We show that the entire 'barrier' layer of thickness much larger than the typical c axis coherence lengths of cuprates exhibits a Meissner effect at temperatures well above Tc' but below Tc. The temperature dependence of the effective penetration depth and superfluid density in different layers indicates that superfluidity with long-range phase coherence is induced in the underdoped layer by the proximity to optimally doped layers; however, this induced order is very sensitive to thermal excitation.Comment: 7 pages, 7 figures + Erratu

Is Multimedia Multisensorial? - A Review of Mulsemedia Systems

© 2018 Copyright held by the owner/author(s). Mulsemedia - multiple sensorial media - makes possible the inclusion of layered sensory stimulation and interaction through multiple sensory channels. e recent upsurge in technology and wearables provides mulsemedia researchers a vehicle for potentially boundless choice. However, in order to build systems that integrate various senses, there are still some issues that need to be addressed. is review deals with mulsemedia topics remained insu ciently explored by previous work, with a focus on multi-multi (multiple media - multiple senses) perspective, where multiple types of media engage multiple senses. Moreover, it addresses the evolution of previously identi ed challenges in this area and formulates new exploration directions.This article was funded by the European Union’s Horizon 2020 Research and Innovation program under Grant Agreement no. 688503

Biaxial strain tuning of exciton energy and polarization in monolayer WS2

We perform micro-photoluminescence and Raman experiments to examine the impact of biaxial tensile strain on the optical properties of WS2 monolayers. A strong shift on the order of -130 meV per % of strain is observed in the neutral exciton emission at room temperature. Under near-resonant excitation we measure a monotonic decrease in the circular polarization degree under applied strain. We experimentally separate the effect of the strain-induced energy detuning and evaluate the pure effect coming from biaxial strain. The analysis shows that the suppression of the circular polarization degree under biaxial strain is related to an interplay of energy and polarization relaxation channels as well as to variations in the exciton oscillator strength affecting the long-range exchange interaction.Comment: 29 pages, 11 figure