Speaker
Description
In 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 electromagnetic scattering and nano-photonics. Specifically, I will demonstrate how Fisher Information can be maximised through wavefront shaping and quantum state engineering [1,2]. Quite remarkably, 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 as a physical quantity that propagates through space and that can resonate, diffract, and interfere [4]. Finally, I will also discuss how such concepts can be generalised to the flow of Fisher Information through Artificial Neural Networks [5].
[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).
[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).