134,676 research outputs found
Fisher information in scattering problems and neural networks
No full textIn my talk, I will discuss recent progress in applying the concept of Fisher information to the problem of estimating system parameters in complex scattering environments, such as inside or behind a disordered medium [1,2,3]. We have recently realised that such tools can also be successfully applied to artificial neural networks, in particular to define the performance limit of a network in extracting information from a complex system.
[1] Maximum information states for coherent scattering measurements, D. Bouchet, S. Rotter, and A. P. Mosk, Nature Physics 17, 564 (2021).
[2] Optimal control of coherent light scattering for binary decision problems, D. Bouchet, L. M. Rachbauer, S. Rotter, A. P. Mosk, and E. Bossy, Phys. Rev. Lett. 127, 253902 (2021).
[3] Invariance property of the Fisher information in scattering media, M. Horodynski, D. Bouchet, M. Kühmayer, and S. Rotter, Phys. Rev. Lett. 127, 233201 (2021)
Fisher Information in Electromagnetism
No full textIn my talk, I will discuss recent progress in applying the concept of classical and
quantum Fisher informa;on to the problem of estimating system parameters in
electromagnetic scattaering and nano-photonics. Specifically, I will demonstrate how Fisher Information can be maximised through wavefront shaping and quantum state engineering [1,2]. Quite interestingly, the density and flux of Fisher information satisfy a fundamental continuity equation – in analogy to the Poynting theorem for the density and flux of energy in a radiation field [3]. This viewpoint allows us to identify Fisher information a physical quantity that propagates through space and that can resonate, diffract, and interfere [4]. Finally, I will also say a few words about how such concepts can be generalised to the flow of Fisher Information through Artificial Neural Networks [5].
[1] Maximum information states for coherent scattaering measurements, D. Bouchet, S. Rotter, and A. P. Mosk, Nature Physics 17, 564 (2021).
[2] How to find optimal quantum states for optical micromanipulation and metrology in complex scattering problems, L. M. Rachbauer, D. Bouchet, U. Leonhardt, and S. Rotter, J. Opt. Soc. Am. B 41, 2122 (2024)
[3] Continuity equation for the flow of Fisher information in wave scattering, J. Hüpfl, F. Russo, L. M. Rachbauer, D. Bouchet, J. Lu, U. Kuhl, and S. Rotter, Nature Physics 20, 1294 (2024)
[4] Controlling the flow of information in optical metrology, M. Weimar, H. Zhou, L. Neubacher, T. A. Grant, J. Hüpfl, K. F. MacDonald, S. Rotter, and N. I. Zheludev, arXiv:2508.13640
[5] Fisher information flow in artificial neural networks, M. Weimar, L. M. Rachbauer, I.
Starshynov, D. Faccio, L. Adilova, D. Bouchet, and S. Rotter, Phys. Rev. X 15, 031072 (2025
Liquid helium flows around an oscillating cylinder
No full textThe complementary flows of normal viscous liquid helium (He I) and of superfluid helium (He II) around an oscillating obstacle, of rectangular cross-section, have been studied experimentally by using the particle tracking velocimetry technique, with solid deuterium particles. The observed particle behaviour in He II is very similar to that seen in He I. It seems therefore that, without some kind of special forcing acting differently on each superfluid helium component, on length scales which the experiment can access, the oscillating quantum flow mimics the classical one
Blackbody radiation and the Weyl law in disordered media
No full textIn my talk, I will discuss an interesting property of blackbody radation when it propagates through complex media, such as disordered materials. As it turns out, the average time spent by the radiation in such a system–or, equivalently, its average path length–is entirely independent of whether the system is strongly disordered (and therefore opaque) or very weakly disordered (and therefore transparent). This property is linked to the so-called "Weyl law", that was discovered in 1911 by Hermann Weyl and allows one to estimate the density of states of a system just based on its geometrical parameters. After introducing this "path length invariance" [1] and its experimental implementations [2,3], I will show how these insights can be connected to information theory [4] and to the forces of the quantum vacuum [5].
[1] R. Pierrat, P. Ambichl, S. Gigan, A. Haber, R. Carminati, and S. Rotter, PNAS 111, 17765 (2014)
[2] R. Savo, R. Pierrat, U. Najar, R. Carminati, S. Rotter, and S. Gigan, Science 358, 765 (2017)
[3] M. Davy, M. Kühmayer, S. Gigan, and S. Rotter, Communications Physics 4, 85 (2021)
[4] M. Horodynski, D. Bouchet, M. Kühmayer, and S. Rotter, Phys. Rev. Lett. 127, 233201 (2021)
[5] L. M. Rachbauer, D. Bouchet, U. Leonhardt, and S. Rotter (manuscript in preparation
Non-Hermitian Topology in Lasers and Anti-Lasers
No full textn my presentation, I will first speak about the topological aspects of encircling an exceptional point (EP) in a laser and the corresponding chiral state transfer [1]. Building on the insight that EPs can also be identified in the absorption spectra of anti-lasers [2], I will present experimental results on the chiral and degenerate perfect absorption at an EP [3]. Finally, I will show how not only two modes can be critically coupled, but more than a thousand – leading to a massively degenerate coherent perfect absorber for arbitrary incoming wavefronts [4].
[1] A. Schumer, Y. G. N. Liu, J. Leshin, L. Ding, Y. Alahmadi, A. U. Hassan, H. Nasari, S. Rotter, D. N. Christodoulides, P. LiKamWa, and M. Khajavikhan, Science 375, 884 (2022)
[2] W. R. Sweeney, C. W. Hsu, S. Rotter, and A. D. Stone, Phys. Rev. Lett. 122, 093901 (2019)
[3] S. Soleymani, Q. Zhong, M. Mokim, S. Rotter, R. El-Ganainy, and S. K. Özdemir, Nature Commun. 13, 599 (2022)
[4] Y. Slobodkin, G. Weinberg, H. Hörner, K. Pichler, S. Rotter, and O. Katz, Science 377, 995 (2022
BAG (4. Senat), Urteil vom 11.09.1991 - 4 AZR 71/91 (2. Instanz: LAG München) [Urteilsanmerkung]
No full textUrteilsanmerkung [Tarifmacht dt. Tarifvertragsparteien für ausschließl. im Ausland zu erfüllende Arbeitsverträge sowie Einwirkungspflicht d. Arbeitgebers beim Firmentarif hinsichtlich abhängiger Unternehmen] / Wilhelm Dütz ; Stephan Rotter. - In: Deutschland / Bundesarbeitsgericht: Nachschlagewerk des ... AP Internat. Privatrecht. Arbeitsrecht. Nr. 29 (1994, Bl. 468-474
The concept of Fisher information in wave scattering
No full textIn my talk, I will discuss recent progress in applying the concept of classical and quantum Fisher information to the problem of estimating system parameters in complex environments, such as inside or behind a disordered medium. In particular, I will demonstrate how Fisher Information can be maximised through wavefront shaping and quantum state engineering [1,2]. Quite interestingly, the density and flux of Fisher information satisfy a fundamental continuity equation – in analogy to the Poynting theorem for the density and flux of energy in a radiation field [3]. If time permits, I will also say a few words about how such concepts can be generalised
to the flow of Fisher Information through Artificial Neural Networks.
[1] Maximum information states for coherent scattering measurements, D. Bouchet, S. Rotter, and A. P. Mosk, Nature Physics 17, 564 (2021).
[2] How to find optimal quantum states for optical micromanipulation and metrology in complex scattering problems, L. M. Rachbauer, D. Bouchet, U. Leonhardt, and S. Rotter, J. Opt. Soc. Am. B 41, 2122
(2024).
[3] Continuity equation for the flow of Fisher information in wave scattering, J. Hüpfl, F. Russo, L. M. Rachbauer, D. Bouchet, J. Lu, U. Kuhl, and S. Rotter, Nature Physics 20, 1294 (2024)
The concept of Fisher information in wave scattering
No full textIn my talk, I will discuss recent progress in applying the concept of classical and quantum Fisher information to the problem of estimating system parameters in complex environments, such as inside or behind a disordered medium. In particular, I will demonstrate how Fisher Information can be maximised through wavefront shaping and quantum state engineering [1,2]. Quite interestingly, the density and flux of Fisher information satisfy a fundamental continuity equation - in analogy to the Poynting theorem for the density and flux of energy in a radiation field [3]. If time permits, I will also say a few words about how such concepts can be generalised to the flow of Fisher Information through Artificial Neural Networks.
[1] Maximum information states for coherent scattering measurements, D. Bouchet, S. Rotter, and A. P. Mosk, Nature Physics 17, 564 (2021).
[2] How to find optimal quantum states for optical micromanipulation and metrology in complex scattering problems, L. M. Rachbauer, D. Bouchet, U. Leonhardt, and S. Rotter, J. Opt. Soc. Am. B 41, 2122 (2024)
[3] Continuity equation for the flow of Fisher information in wave scattering, J. Hüpfl, F. Russo, L. M. Rachbauer, D. Bouchet, J. Lu, U. Kuhl, and S. Rotter, Nature Physics 20, 1294 (2024
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Coherent perfect absorption and emisson of light in non-Hermitian and time-varying media
No full textIn this talk, I will speak about our recent work on coherent perfect absorption (CPA) [1,2] and emission [3] of light in tailor-made resonators. I will highlight, in particular, the possibility to engineer spatial and spectral degeneracies for broadband absorption of arbitrary wavefrontsat an exceptional point as well as the topological aspects associated with perfect emission of thermal radiation. In the second part of my presentation, I will present new insights on the CPA effect in time-varying media, which can be well described by a pseudo-unitary Floquet scattering matrix [4].
[1] Y. Slobodkin, G. Weinberg, H. Hörner, K. Pichler, S. Rotter, and O. Katz, Science 377, 995 (2022)
[2] H. Hörner, L. Wild, Y. Slobodkin, G. Weinberg, O. Katz, and S. Rotter, Phys. Rev. Lett. 133, 173801 (2024).
[3] M. S. Ergoktas, A. Keçeba¸s, K. Despotelis, S. Soleymani, G. Bakan, A. Kocaba¸s, A. Principi, S. Rotter, ¸S. K. Özdemir, and C. Kocaba¸s, Science 384, 1122 (2024).
[4] D. Globosits, J. Hüpfl, and S. Rotter, Phys. Rev. A 110, 053515 (2024)
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