Recent years have witnessed a remarkable surge in interest for the electronic properties of new materials, particularly when excited by electromagnetic radiation. This is a very vast domain of research that encompasses all sorts of nano-objects (metallic films and nanoparticles, carbon nanotubes, semiconductor quantum dots,…), new materials like graphene, as well as metamaterials whose structure can be engineered so as to display some particular optical properties. In this project, we will focus our attention on metallic nano-objects and the composite metamaterials that can be constructed out of them, such as networks of interacting nanoparticles. Standard methods to study the electron response – such as the time-dependent density functional theory or Hartree-Fock equations – are computationally very costly in terms of run time and memory storage. On the other hand, recent approaches rely on much simpler methods based on improvements of the classical Mie theory. Here, we propose to develop and implement a set of quantum hydrodynamic (QHD) models that are sufficiently simple to be run on standard computers (desktop PC or small university cluster), but contain enough physics to study the electron response beyond the Mie model – in particular nonlinear, nonlocal, and quantum effects. The combination of flexibility and accuracy of QHD models makes them an ideal tool to investigate many open problems in the emerging field of nanoplasmonics. Using this approach, several configurations of nano-objects will be studied, including dimers and trimers of metallic nanoparticles and nanorods, metal-dielectric multilayers, nanoparticles in the vicinity of a thin metal film, and arrays of nanoparticles interacting via the dipole force.
The realm of topological photonics relies on extreme flexibility of optical media for sculpting Hamiltonians with arbitrary properties in real and synthetic dimensions. Topological effects in the optical domain can provide robust waveguiding and stable lasing, which is of extreme interest for integrated photonics. A powerful tool to imprint topological properties is periodic Floquet driving, which maps the energy bands onto a periodic quasienergy spectrum. Even richer physics was predicted to emerge if interactions are added into the system. However, the experimental studies of interacting Floquet matter remained scarce due to absence of suitable platforms. This project relies on a system of coupled fiber rings to realize a synthetic lattice for the study of interacting topological Floquet phases. This platform provides a unique combination of intrinsic Floquet nature due to periodicity of the light propagation in rings, full control over complex couplings, and tunable Kerr nonlinearities in the fibers, thus allowing to engineer many-body Floquet Hamiltonians and study topological physics inaccessible with other systems. Based on these unique features, the action aims at demonstration of novel topological Floquet phases and topological pumping in presence of interactions. This project stays at the cornerstone between topological physics, photonics, and nonlinear fiber optics, and perfectly fits the applicant’s experience for preparing him for a future career as an independent researcher.
Certain papillomaviruses (PVs) are a major public health concern as in humans they are responsible for virtually all cases of cervical and anal cancer, and for a fraction of cancers on the penis, vagina, vulva and oropharynx. But oncogenic PVs are actually an unfortunate exception, as most PVs cause asymptomatic infections, and a few cause benign, wart-like lesions. Despite the efforts directed towards the understanding of the different clinical manifestations of infection, our knowledge on PV evolution remains fragmentary. Oncogenic human PVs arose recently, after acquiring the E5, E6 and E7 genes. The integration of the E5 proto-oncogene in the ancestral AlphaPV genome allowed viruses to evade host immune response. Thereafter E6 and E7 acquired the ability to target essential tumor suppressor proteins, paving the way for carcinogenesis. Tracking the evolutionary history of the E5, E6 and E7 oncogenes will thus help understand the emergence of oncogenic human PVs. Regarding the deep roots of PVs, small DNA viruses may share a common ancestor as they encode proteins sharing similar functions and domains, but their evolutionary origin is still an enigma. Here I propose to apply an evolutionary medicine approach, combining in silico and wet-lab approaches, to study key events that occurred during PV genome evolution. We will go back into history and study how and when certain PVs became oncogenic. We will resurrect the ancestral oncogenes, and experimentally test hypotheses about the function of the resurrected proteins in different environmental contexts. We will then generate a comprehensive scenario modelling the appearance of the modern PV genome and the emergence of the oncogenic phenotype of certain PVs. Finally we will explore the relationships between small DNA viruses and test whether they may have a common origin. Our ultimate aim is to understand why a few PVs are oncogenic for a few host species, while most PVs cause asymptomatic infections in most hosts.