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Martin Obstbaum

Publications and source records attributed to Martin Obstbaum.

2 recordsLinked to original sources

Revitalizing Public Urban Places through Cultural and Political Memory: A Technological Approach with LLMs and Augmented Reality

This paper explores the intersection of memory, place, and identity, examining how new technologies, particularly Apple Vision Pro, can illuminate this nexus. Leveraging digital twins and virtual reality, it investigates how memory is woven into landscapes and urban environments of cultural and historical significance, identifying visual elements that evoke memory and heritage. Applications such as Apple Vision Pro can facilitate image extension to define place identity, informing viewers about cultural and political entities across timelines. Visual storytelling can showcase the evolution of landscapes and the preservation of cultural heritage, while Virtual Reality (VR) enables the recreation of historical landscapes and urban-scapes. This immersive approach invites users to transcend temporal boundaries and experience the past dynamically. Semantic Image Search can support research by uncovering images related to monuments, tradition, or cultural identity. This research introduces a methodology to connect digital twins and virtual environments with urban and non-urban landscapes to illustrate cultural, historical, and environmental sustainability. Central to this approach is defining the resilience of the current state, its future evolution, and the significance of the past. These technologies facilitate a historical and cultural embrace while evoking the feeling of returning to a specific place years later. The methodology outlines the integration of technologies needed to revitalize public urban places through cultural and political memory. Through these applications, this paper contributes to research on digital twins of spaces, urban transformation, and cultural heritage preservation. By offering insights into the relationship between memory, place, and identity in the digital age, it supports a deeper understanding of our collective past and its impact on the present.

cs.CY

Experimental observation of a large ac-spin Hall effect

In spinelectronics the spin degree of freedom is used to transmit and store information. Ideally this occurs without net charge currents in order to avoid energy dissipation due to Joule heating. To this end the ability to create pure spin currents i.e.without net charge transfer is essential. Spin pumping is the most popular approach to generate pure spin currents in metals, semiconductors, graphene, and even organic materials. When the magnetization vector in a ferromagnet (FM) - normal metal (NM) junction is excited the spin pumping effect leads to the injection of pure spin currents in the normal metal. The polarization of this spin current is time dependent and contains a very small dc component. The dc-component of the injected spin current has been intensely studied in recent years and has given rise to controversial discussions concerning the magnitude the spin Hall angle which is a material dependent measure of the efficiency of spin to charge conversion . However in contrast to the rather well understood dc component the two orders of magnitude larger ac component has escaped experimental detection so far. Here we show that the large ac component of the spin currents can be detected very efficiently using the inverse spin Hall effect (ISHE). The observed ac-ISHE voltages are one order of magnitude larger than the conventional dc-ISHE measured on the same device. The spectral shape, angular dependence, power scaling behavior and absolute magnitude of the signals are in line with spin pumping and ISHE effects. Our results demonstrate that FM-NM junctions are very efficient sources of pure spin currents in the GHz frequency range and we believe that our result will stimulate the emerging field of ac spintronics.

cond-mat.mes-hall