[Zurück]

S. Rotter:
"Non-Hermitian channels of invisibility across complex media";
Vortrag: Virtual seminar series on Pseudo-Hermitian Hamiltonians in Quantum Physics, London (eingeladen); 05.11.2020.

Waves typically propagate very differently through a homogeneous medium like free space than through an inhomogeneous medium like a complex dielectric structure. It has thus been quite surprising to find that one-dimensional scattering systems can be engineered in such a way that by way of the gain and loss added to them, they become not only reflection-less, but entirely scattering-free [1,2], even for pulses propagating through them [3]. Our most recent insight is that a straightforward way to extend these non-Hermitian features to two-dimensional space is to map the wave solutions in free space to those inside a suitably designed non-Hermitian potential landscape such that both solutions share the same spatial distribution of their wave intensity [4]. This mapping turns out to be broadly applicable as a design protocol for a special class of non-Hermitian media across which specific incoming waves form scattering-free propagation channels. This protocol naturally enables the design of structures with a broadband unidirectional invisibility for which outgoing waves are indistinguishable from those of free space. We illustrate this concept through the example of a beam that maintains its Gaussian shape while passing through a randomly assembled distribution of scatterers with gain and loss.
[1] K. G. Makris, A. Brandstötter, P. Ambichl, Z. H. Musslimani, and S. Rotter, Light Sci. Appl. 6, e17035 (2017)

[2] E. Rivet, A. Brandstötter, K. G. Makris, H. Lissek, S. Rotter, and R. Fleury, Nature Physics 14, 942 (2018)

[3] A. Brandstötter, K. G. Makris, and S. Rotter, Phys. Rev. B 99, 115402 (2019)

[4] K. G. Makris, I. Kresić, A. Brandstötter, and S. Rotter, Optica 7, 619 (2020)

https://vphhqp.com/the-seminars/