Thesis Director: Prof. S. N. Henein,
\r\nAdvanced Manufacturing doctoral program
\r\nThesis Nr. 11844
\r\n
\r\nTo take part in the public defense, please contact directly the speaker
Please join us for the QSE Center Quantum Seminar with Ulf Leonhardt from the Weizmann Institute of Science who will give a talk about \"Fibre-optical analogue of the event horizon: Hawking radiation and backreaction\" on Thursday July 2nd from 12:00 to 13:30.
\r\nLocation:
\r\n
\r\nPizzas will be available at 12:00. All PhDs, postdocs, students, group leaders, and PIs are welcome to join us.
\r\n
\r\nTITLE: \"Fibre-optical analogue of the event horizon: Hawking radiation and backreaction\"
\r\n
\r\nABSTRACT:
\r\nHawking radiation - the emission of quantum particles at the event horizon of a black hole - connects gravity with quantum mechanics and thermodynamics; the Bekenstein-Hawking entropy has been the benchmark for potential quantum theories of gravity. But Hawking radiation has never been observed in astronomy, only in laboratory analogues and the chances of ever observing it in space are astronomically small. The energy of Hawking radiation must come from the gravitational field around the black hole, but how field quanta generate Hawking quanta has been unknown. In this talk I report on experimental and theoretical evidence for the process that generates Hawking radiation in a fibre-optical analogue of the event horizon. There, as in gravity, it has been believed that Hawking radiation comes from a complicated, cascaded process, but we have found a simple, direct process and measured its backreaction on the field. Our findings suggest an equally direct process for other laboratory analogues and perhaps also for gravitational fields, shedding light on how black holes might radiate.
\r\n
\r\nBIO:
\r\nUlf Leonhardt joined the Weizmann Institute of Science as Professor of Physics in November 2012 after an international career. Ulf Leonhardt was born in Schlema, in former East Germany, on October 9th 1965. He studied physics at Friedrich-Schiller University Jena, at Moscow State University and at Humboldt University Berlin where he received his PhD in 1993. He was a Visiting Scholar at the Oregon Center for Optics in the US, a Habilitation Fellow at the University of Ulm in Germany and a Göran-Gustafson and Feodor-Lynen fellow at the Royal Institute of Technology in Stockholm, Sweden. From 2000 to 2012, he was the Chair in Theoretical Physics at the University of St Andrews, UK. Ulf Leonhardt also had various visiting positions: in 2008 he was a visiting professor at the National University of Singapore and in 2011 at the University of Vienna; in 2012/13 he was an adjunct professor at South China Normal University, fsince 2026 he is a Global Fellow and visiting professor at Vienna Institute of Technology.
\r\n
\r\nUlf Leonhardt is the first from former East Germany to receive the Otto Hahn Award of the Max Planck Society. For his PhD thesis he received the Tiburtius Prize of the Senate of Berlin. In 2006 Scientific American listed him among the top 50 policy, business and research leaders of the world of that year. In 2008 he received a Royal Society Wolfson Research Merit Award and in 2009 a Theo Murphy Blue Skies Award of the Royal Society. In 2012 he received a thousand-talent award of China. He is a Fellow of the Institute of Physics and of the Royal Society of Edinburgh.
The two-week event will broadly focus on spectral geometry, hyperbolic surfaces, and number theory, with the primary goal of fostering connections between these areas. By bringing together young researchers and engaging them in ongoing discussions around these topics, we aim to encourage collaboration and stimulate progress across these fields.
\r\nThe first week will feature mini-courses delivered by young participants, providing an opportunity for early-career researchers to share their expertise.
\r\nThe second week will consist of research-level talks by experts, highlighting recent developments in the field.
Thesis Director: Prof. B. E. Ferreira De Sousa Correia,
\r\nChemistry and Chemical Engineering doctoral program
\r\nThesis Nr. 11408
\r\n
\r\nTo take part in the public defense, please contact directly the speaker
Thesis Directors: Prof. Y. Perriard, Dr Y. R. C. Civet
\r\nMicrosystems and Microelectronics doctoral program
\r\nThesis Nr. 11802
\r\n
\r\nTo take part in the public defense, please contact directly the speaker
The availability, diversity, and function of biological matter are inherently shaped by geography. Climate, ecosystems, agriculture, and food systems determine not only which biomass resources emerge across regions, but also the biological architectures and material opportunities they embody. In this presentation, biological matter is explored as a materials platform spanning plant tissues, fungal networks, marine organisms, and biomass-derived colloidal systems, with emphasis placed on how the organization and composition of such natural precursors can guide their engineering into sustainable material systems.
\r\nThemes of (i) biofabrication, using microbial precursors to generate guided assemblies across scales, (ii) natural fiber and bio-colloidal systems, considering their isolation and assembly into functional materials, and (iii) ecosystem integration, considering opportunities to address climatic and other environmental challenges, will be covered. Regarding the latter, examples including arid soil restoration, marine infrastructure remediation, and hybrid living materials are presented as case studies toward deployable systems. For bio-colloidal systems, their inherent advantages and limitations relative to synthetic colloidal systems will also be discussed.
\r\nUltimately, introducing sustainability into the material sector extends beyond precursor selection alone, as ecosystem integration and supply-chain considerations become increasingly critical – particularly as the regionalization of biomass circularization gains importance. The seminar concludes with a brief perspective on technology transfer and innovation as extensions of scientific research toward broader societal impact.
\r\n
\r\nDr. Blaise Tardy joined Khalifa University in January 2022 as an Assistant Professor. After graduating from École Polytechnique Fédérale de Lausanne in 2009, he obtained his Ph.D. in Chemical and Biomolecular Engineering from The University of Melbourne in 2015 and was subsequently a research fellow at Aalto University from 2016 to 2022. His research bridges colloidal and interfacial sciences, bioengineering, and sustainable materials, with an emphasis on biological matter as a platform for engineering multiscale material systems. His work spans biofabrication, biomass-derived colloids, natural fibers, and sustainable materials obtained from biotechnology, agriculture, aquaculture, and food-system side streams, with applications linked to the growing circular bioeconomy. This interdisciplinary combination of expertise has led to highly recognized publications featured in international press releases and published in leading journals in materials and nanoscience. His broader objective is to connect fundamental science, innovation, and technology transfer toward deployable material systems with impact beyond the laboratory.
\r\n
Pickering emulsions (PEs) have emerged as attractive platforms for the fabrication of porous and other novel functional materials. In this talk, I will first discuss strategies that can be exploited to drive particles to the interface. Thereafter, rules for the designing Pickering emulsions and their printability will be discussed. In particular, we will focus on hetero-aggregation-driven particle adsorption to fluid interfaces, which is crucial for to ensure stability of Pickering emulsions. By controlling particle interactions through parameters such as pH and particle concentration, the microstructure and rheological properties of PEs can be tailored to achieve excellent printability and shape retention during direct ink writing. Thereafter, printable PEs are used to fabricate three-dimensional architectures that are subsequently dried and sintered to obtain hierarchically porous ceramics. The resulting porous structures are characterized in terms of their microstructure, pore size, and porosity. As a demonstration, the porous ceramics are employed as supports for gold nanoparticles and evaluated in the catalytic reduction of 4-nitrophenol. The proposed approach provides a simple, scalable, and versatile framework for designing 3D-printable Pickering emulsions and developing functional porous materials for diverse applications.
\r\nKEYWORDS: 3D Printing, Pickering Emulsions, Porous Materials, Catalyst Support
\r\nReferences:\r\n