Department of Complex Matter
Jamova cesta 39, 1000 Ljubljana, Slovenia

Dynamics of Quantum matter

We explore non-equilibrium many-body dynamics in quantum systems that experience symmetry-breaking, topological, or jamming transitions. These systems encompass superconductors, charge-density wave, and magnetic materials.

Experimental Soft Matter Physics

The research is conducted within the “Light and Matter” research program. The interaction of light with matter is one of the most important fields of physics and optical processes are indispensable in many branches of modern industry.

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April 11, 2024
Dr. Dragan Mihailović, a leading researcher in the field of quantum systems at the Jožef Stefan Institute (IJS), has successfully won the third project of the European Research Council (ERC), HIMMS (High-Resolution ...
Home / Events / The maximum refractive index of optical materials: from quantum optics to quantu…

The maximum refractive index of optical materials: from quantum optics to quantum chemistry

February 15, 2024 , 11:15 , Seminar Room for Physics
Darrick Chang (The Institute of Photonic Sciences (IFCO), Spain)


It is interesting to observe that all known optical materials have a refractive index that is of order unity at visible/telecom wavelengths. However, 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 develop minimal but unifying models to understand the index of a collection of atoms as a function of density, ranging from the “quantum optics” regime of well-isolated atoms, to the “quantum chemistry” regime of real materials where many-electron behavior becomes relevant. Importantly, our models simultaneously account for non-perturbative multiple light scattering, which is a key factor in what makes the problem surprisingly rich and complex. Our work suggests 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 and the associated potential for miniaturization of optical devices and enhancement of optical resolution.