Topological complex electromagnetic waves give access to nontrivial light-matter interactions and provide additional degrees of freedom for information transfer. For instance, topologically stable quasiparticles or skyrmions have been demonstrated in quantum fields, solid-state physics, and magnetic materials, but only recently observed in photonic fields, triggering fast expanding research across different spectral ranges and applications. Here I introduce an extended family of photonic skyrmions within a unified framework, starting from fundamental theories to experimental generation and topological control in spatiotemporally structured light. I will further highlight generalized classes of optical topological quasiparticles beyond skyrmions and outline their exotic topological robust properties, emerging applications, future trends, and open challenges. A complex vectorial field structure of optical quasiparticles with versatile topological characteristics controlled in ultrasmall and ultrafast space-time domain emerges as an important feature in modern spin-orbital optics, imaging and metrology, optical informatics, and topological and quantum technologies.

One of the greatest problems in modern nano-electronics is heat management. As the transistors get smaller that amount of heat generated becomes exponentially larger. Due to the stacked architecture of microprocessors a solution for the heat management requires materials that are extreme anisotropic for heat conduction. Using basic quantum mechanical principles of phase coherence and destructive quantum interference we created, at CA2DM, a thin film 3D carbon allotrope that is metallic at room temperature and has record breaking electrical and thermal transport anisotropies.

In addition to reviewing the history of uncertainty relations, starting with Heisenberg’s work in 1927, the talk will discuss how all the standard inequalities – for products or sums of variances – follow from one basic equation.

Reference: arXiv:2310.05039; Phys. Lett. A 494, 129278 (2024).

Metasurfaces have recently emerged as a new class of optical devices, which can shape light beams at sub-wavelength scales. Due to their compact footprint and large-scale manufacturability using conventional semiconductor processes, they are currently attracting significant attention in optoelectronics as potential candidates to replace conventional lenses in future optical systems. They can not only mimic the functions of conventional optical elements but also offer unique functionalities not achievable by conventional optics. Particularly attractive is to make these components fully tunable to create dynamic sub-wavelength control of light. In this talk, I will first show several examples of flat optical elements demonstrating superior functionalities such as extra-large-numerical aperture focusing or extra-large field of view imaging. I will then switch to tunable metasurfaces demonstrating how dynamic control of individual metasurface pixels helps to create spatial light modulators with ~1 micron pixel pitch for dynamic beam steering and tunable holography.

Hermitian symmetry is commonly imposed on quantum Hamiltonians, to ensure the conservation of probability. In recent years, however, researchers have realized that non-Hermitian Hamiltonians, which govern classical or quantum systems subject to probability or energy non-conserving effects, can have rich behaviors qualitatively distinct from the Hermitian case. In this talk, I describe several recently-discovered phenomena in non-Hermitian periodic media, including gain/loss induced topological states, non-Hermitian Dirac quasiparticles, and bound states forming complex energy continua. These phenomena challenge well-established principles from the Hermitian world, such as the strict dichotomy between bound states and free states. They can be realized and studied on a variety of accessible experimental platforms, such as synthetic photonic lattices.

Large quantum systems typically thermalize, which is in itself a very interesting problem. On their way to thermalization, we show that large quantum systems can manifest different dynamics which can be classified depending on their symmetries and the observables we are considering.

We will also present how non-equilibrium steady states can be understood as a prethermal state emerging while the system is on the path towards thermalization, and how this can help their experimental study in today's quantum processors. Last, we will discuss recent trends for the simulation of such many-body quantum systems, with an emphasis on neural network quantum states.

Flatbands arise in certain periodic lattices when symmetries or fine-tuning produce energy bands with a vanishing wave group velocity, resulting in perfect wave localization. Flatband-induced localization leads to remarkably sharp sensitivity to perturbations, enabling a variety of interesting quantum and classical strong interaction phenomena. Originally a theoretical curiosity, advances in nanofabrication now allow flatband physics to be observed in a variety of settings including electronic moire materials and photonic crystals. In this talk I will survey the history of this field before discussing emerging applications to the design of giant light-matter interactions using fine-tuned arrays of silicon nanoparticles.