



Understanding the electronic properties of valence electrons in nano-objects is not only of fundamental interest but also essential for the design of next-generation optoelectronic devices. In such systems, electron confinement in low-dimensional structures gives rise to unique properties.
These properties are inherently linked to fundamental characteristics of matter and the associated quantum fluctuations. More recently, concepts such as quantum entanglement and Fisher quantum information have been connected to spectroscopic properties. On the other hand, these spectroscopic properties can be probed through experimental techniques, including absorption, photoemission, and inelastic X-ray scattering.
Recently, we demonstrated that the widely used formalism to study isolated nano-objects was not adapted, and that it affected the calculated optical properties. We evidenced, theoretically and experimentally, that for the two-dimensional objects, the optical response contained, beyond the transverse contribution, a resonance coming from the plasmon, which corresponds to a longitudinal response. The role of the interfaces revealed to be determinant. The project of this year is to have a critical analysis of the optical properties of unidimensional objects.
Beyond the fundamental characterization of the 1D dielectric function, this research will explore its connection to quantum entanglement and Fisher quantum information—concepts that, to date, have not been investigated in low-dimensional systems.

