QuCoLiMa Talk - Darrick Chang - The maximum refractive index of optical materials: from quantum optics to quantum chemistry
Darrick Chang – ICFO
The maximum refractive index of optical materials: from quantum optics to quantum chemistry
Talk on-site in Mainz
All talks – regardless of where the talks are given – are livestreamed via Zoom and can also be watched together at the following locations:
– Erlangen: Livestream/Presentation in lecture hall F + open sandwiches in the foyer afterwards
– Saarbrücken: Livestream/Presentation in Konferenzraum Informatik (Geb. E1.1, Room 407)
– Mainz: tba
It is interesting to observe that all known optical materials have a refractive index that is of order unity at visible/telecom wavelengths. Furthermore, it is not easy to reconcile this with the fact that the individual atoms making up the material are well-known to have a huge optical response near resonance, when isolated, as characterized by a scattering cross section that is much larger than the physical size of the atom. Here, we discuss the role that non-perturbative collective effects and multiple scattering of light have on determining the index of a collection of atoms, starting from the “quantum optics” regime of well-isolated atoms, to the “quantum chemistry” regime relevant for real-life solids. We elucidate various mechanisms by which the index can be limited, either by pure electrodynamic effects or by many-body effects associated with quantum chemistry. We develop a minimal model suggesting that an ultrahigh index material (n~30) with low losses is in principle allowed by the laws of nature. If realizable, such a material would have profound implications for optical technologies, due to the extreme reduction of optical wavelength.
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QuCoLiMa Talks are the weekly seminar of the collaborative research center TRR 306 QuCoLiMa (Quantum Cooperativity of Light and Matter). The talks are given by (external) experts, whose research falls within the scope of QuCoLiMa.