Refine
Year of publication
Document Type
- Article (450)
- Master's Thesis (411)
- Conference Proceeding (395)
- Part of a Book (230)
- Book (107)
- Report (28)
- Other (18)
- Doctoral Thesis (14)
- Working Paper (9)
- Preprint (5)
- Part of Periodical (4)
- Periodical (3)
- Bachelor Thesis (1)
- Habilitation (1)
Institute
- Wirtschaft (350)
- Forschungszentrum Mikrotechnik (252)
- Technik | Engineering & Technology (192)
- Forschungszentrum Business Informatics (167)
- Department of Computer Science (Ende 2021 aufgelöst; Integration in die übergeordnete OE Technik) (164)
- Soziales & Gesundheit (145)
- Forschungsgruppe Empirische Sozialwissenschaften (117)
- Forschungszentrum Human Centred Technologies (102)
- Forschungszentrum Energie (88)
- Didaktik (mit 31.03.2021 aufgelöst; Integration ins TELL Center) (68)
Keywords
- Social Work (18)
- Organizational Studies, Economic Sociology (17)
- Social Structure, Social Inequality (17)
- Digitalisierung (14)
- Soziale Arbeit (14)
- Controlling (11)
- Laser ablation (11)
- Y-branch splitter (11)
- arrayed waveguide gratings (11)
- +KDC 122 (9)
In den letzten Jahren hat die Forschung im Bereich queerer Lebenswelten und LGBTIAQ* Thematiken zugenommen und konventionelle Vorstellungen über Geschlechterdichotomien verändert, was zu einer breiteren Akzeptanz verschiedener Identitäten geführt hat. Zudem wurden die Auswirkungen von Diskriminierung auf LGBTIAQ* Personen untersucht, was zur Entwicklung des Minderheitenstressmodell führte. Um Diskriminierung zu bekämpfen und angemessene Unterstützung zu bieten, ist es zentral, queere Themen in die Soziale Arbeit zu integrieren. Es ist wichtig die Sensibilisierung für die Anliegen und Herausforderungen von jungen erwachsenen LGBTIAQ* Personen zu erhöhen und eine queer inklusive Perspektive zu fördern. Insbesondere in Bezug auf junge Erwachsene, die von gängigen heteronormativen Normen abweichen, da diese zu einer vulnerablen Gruppe zählen und marginalisiert sind. In urbanen Regionen wie dem Rheintal in Vorarlberg müsste, wie in urbanen Zentren in Wien herausgefunden wurde, ebenfalls ein dringender Bedarf an einem sicheren Raum und Unterstützungsstrukturen für junge erwachsene LGBTIAQ* Personen bestehen. Die vorliegende Masterarbeit widmet sich dieser Thematik und konzentriert sich auf die Situation im Vorarlberger Rheintal. Dabei stehen im Fokus der Untersuchung die Lebensbewältigung und Lebensgestaltung von jungen queeren Erwachsenen und die strukturellen Herausforderungen, die Gestaltung von Orten sowie die Interaktion mit Menschen. Die Forschungsfrage zielt darauf ab, die Erfahrungen und Herausforderungen dieser Gruppe im Hin- blick auf Soziale Arbeit und die Gestaltung von einem geeigneten Raum zu erforschen. Der Forschungsstand und das theoretische Verständnis werden umfassend dargestellt, wobei Konzepte aus der interkulturellen Sozialen Arbeit, der Queer Theorie, der Identitätskonstruktion und dem Minderheitenstressmodell herangezogen werden. Die methodische Herangehensweise, einschließlich der Auswahl der Interviewmethoden, des Sampling-Prozesses und der Forschungsethik, wird ausführlich beschrieben, um sicherzustellen, dass die Erkenntnisse auf einer soliden methodischen Grundlage basieren. Eine Auswertung der Daten erfolgt in verschiedenen Abschnitten. Die Masterarbeit fasst alle gewonnenen Erkenntnisse zusammen, wobei besondere Aufmerksamkeit auf interkulturelle Perspektiven gelegt wird. Abschließend werden in einer Diskussion und Schlussfolgerung die Besonderheiten des Rheintal Vorarlberg, Limitationen, Ausblicke, Kritik und Reflexion beleuchtet und es werden Handlungsempfehlungen für die Soziale Arbeit formuliert.
Signatures of the optical stark effect on entangled photon pairs from resonantly-pumped quantum dots
(2023)
Two-photon resonant excitation of the biexciton-exciton cascade in a quantum dot generates highly polarization-entangled photon pairs in a near-deterministic way. However, the ultimate level of achievable entanglement is still debated. Here, we observe the impact of the laser-induced ac-Stark effect on the quantum dot emission spectra and on entanglement. For increasing pulse-duration-to-lifetime ratios and pump powers, decreasing values of concurrence are recorded. Nonetheless, additional contributions are still required to fully account for the observed below-unity concurrence.
Strain-induced dynamic control over the population of quantum emitters in two-dimensional materials
(2023)
The discovery of quantum emitters in two-dimensional materials has triggered a surge of research to assess their suitability for quantum photonics. While their microscopic origin is still the subject of intense studies, ordered arrays of quantum emitters are routinely fabricated using static strain-gradients, which are used to drive excitons toward localized regions of the 2D crystals where quantum-light-emission takes place. However, the possibility of using strain in a dynamic fashion to control the appearance of individual quantum emitters has never been explored so far. In this work, we tackle this challenge by introducing a novel hybrid semiconductor-piezoelectric device in which WSe2 monolayers are integrated onto piezoelectric pillars delivering both static and dynamic strains. Static strains are first used to induce the formation of quantum emitters, whose emission shows photon anti-bunching. Their excitonic population and emission energy are then reversibly controlled via the application of a voltage to the piezoelectric pillar. Numerical simulations combined with drift-diffusion equations show that these effects are due to a strain-induced modification of the confining-potential landscape, which in turn leads to a net redistribution of excitons among the different quantum emitters. Our work provides relevant insights into the role of strain in the formation of quantum emitters in 2D materials and suggests a method to switch them on and off on demand.
Synthetic polymers, such as polyamide (PA), inherently possess a moderate number of surface functionalities compared to natural polymers, which negatively impacts the uniformity of metallic coatings obtained through wet-chemical methods like electroless plating. The paper presents the use of a siloxane interlayer formed from the condensation of the hydrolyzed 3-triethoxysilylpropyl succinic anhydride (TESPSA) precursor as a strategy to modify the surface properties of polyamide 6.6 (PA66) fabrics and improve the uniformity of the copper surface coating. The application of the siloxane intermediate coating demonstrates a significant improvement in electrical conductivity, up to 20 times higher than fabrics without the interlayer. The morphology of the coatings was investigated using scanning electron (SEM) and laser confocal scanning microscopy (LSM). In addition, dye adsorption, flexural rigidity, air permeability and contact angle measurements were conducted to monitor the change in the PA66 properties after the siloxane functionalization.
Experimental multi-state quantum discrimination in the frequency domain with quantum dot light
(2022)
The quest for the realization of effective quantum state discrimination strategies is of great interest for quantum information technology, as well as for fundamental studies. Therefore, it is crucial to develop new and more efficient methods to implement discrimination protocols for quantum states. Among the others, single photon implementations are more advisable, because of their inherent security advantage in quantum communication scenarios. In this work, we present the experimental realization of a protocol employing a time-multiplexing strategy to optimally discriminate among eight non-orthogonal states, encoded in the four-dimensional Hilbert space spanning both the polarization degree of freedom and photon energy. The experiment, built on a custom-designed bulk optics analyser setup and single photons generated by a nearly deterministic solid-state source, represents a benchmarking example of minimum error discrimination with actual quantum states, requiring only linear optics and two photodetectors to be realized. Our work paves the way for more complex applications and delivers a novel approach towards high-dimensional quantum encoding and decoding operations.
A quantum-light source that delivers photons with a high brightness and a high degree of entanglement is fundamental for the development of efficient entanglement-based quantum-key distribution systems. Among all possible candidates, epitaxial quantum dots are currently emerging as one of the brightest sources of highly entangled photons. However, the optimization of both brightness and entanglement currently requires different technologies that are difficult to combine in a scalable manner. In this work, we overcome this challenge by developing a novel device consisting of a quantum dot embedded in a circular Bragg resonator, in turn, integrated onto a micromachined piezoelectric actuator. The resonator engineers the light-matter interaction to empower extraction efficiencies up to 0.69(4). Simultaneously, the actuator manipulates strain fields that tune the quantum dot for the generation of entangled photons with fidelities up to 0.96(1). This hybrid technology has the potential to overcome the limitations of the key rates that plague current approaches to entanglement-based quantum key distribution and entanglement-based quantum networks. Introduction
Beyond the Four-Level Model: Dark and Hot States in Quantum Dots Degrade Photonic Entanglement
(2023)
Entangled photon pairs are essential for a multitude of quantum photonic applications. To date, the best performing solid-state quantum emitters of entangled photons are semiconductor quantum dots operated around liquid-helium temperatures. To favor the widespread deployment of these sources, it is important to explore and understand their behavior at temperatures accessible with compact Stirling coolers. Here we study the polarization entanglement among photon pairs from the biexciton–exciton cascade in GaAs quantum dots at temperatures up to ∼65 K. We observe entanglement degradation accompanied by changes in decay dynamics, which we ascribe to thermal population and depopulation of hot and dark states in addition to the four levels relevant for photon pair generation. Detailed calculations considering the presence and characteristics of the additional states and phonon-assisted transitions support the interpretation. We expect these results to guide the optimization of quantum dots as sources of highly entangled photons at elevated temperatures.
In this paper, we consider the question of data aggregation using the practical example of emissions data for economic activities for the sustainability assessment of regional bank clients. Given the current scarcity of company-specific emission data, an approximation relies on using available public data. These data are reported in different standards in different sources. To determine a mapping between the different standards, an adaptation to the Covariance Matrix Self-Adaptation Evolution Strategy is proposed. The obtained results show that high-quality mappings are found. Nevertheless, our approach is transferable to other data compatibility problems. These can be found in the merging of emissions data for other countries, or in bridging the gap between completely different data sets.