Material science and quantum chemistry, among other fields, have shown the hard way that our capacity to solve quantum mechanical problems is severely limited. Exact solutions with 10²³ particles are out of the question, approximate analytical solutions are hard to find and control and numerical approaches suffer from the inherent limitation of representing a quantum problem on a classical computer. In the last two decades or so, the idea of doing quantum simulations, namely finding quantum systems that can solve specific problems has gained considerable traction due to progress in cold atomic gases and in material science. In this talk, the challenges in this field will be reviewed, starting from the reasons why we need such quantum simulators, and then giving several examples in cold atomic gases and condensed matter of realised quantum simulators and the problems that they allowed to tackle.

Photovoltaic solar energy is one of the most important technologies to decarbonize the energy sector. In many regions of the planet, solar energy is the cheapest way to generate electricity.
In this talk, I will first introduce perovskite/silicon tandem solar cells, which allow to overcome the efficiency limit of market -dominant silicon cells with a theoretical limit of 29.4% power conversion efficiency (PCE). Then, I will discuss how photonic concepts were implement ed to reach 29.8% PCE at Helmholtz-Zentrum Berlin. In the second part of my talk, I will discuss why energy yield calculations are important and how modelling can be used for accurate energy-yield modelling.

Over the past 60 years, the formidable task of measuring the complex structure of coherent light has remained elusive. Fortunately, the last decade has seen the rise of a completely novel class of techniques based on computational imaging. These methods represent a paradigm shift away from experimental hardware toward sophisticated computer algorithms. In doing so, computational optics is paving theway to a new generation of high dimensional metrologies, finally providing a route to measure the most extreme events humans can create. This talk will detail the development of single-pulse, broadband computational metrologies specifically designed to measure ultrafast pulses of light across the electromagnetic spectrum.

The spontaneous production of particles due to a gravitational field is one of the cornerstones of the theory of quantum fields in curved spacetime. This effect has an important role in our current understanding of the early phases of the Universe. I will introduce this phenomenon and point out the difficulties that arise when computing physical magnitudes, e.g. the stress-energy tensor.  I will show how we can overcome these issues and how to generalize this description to interacting fields, e.g., to understand the generation of matter during the reheating phase in the inflationary scenario.

The idea of the multifractals is basically contained in the large deviation theory; however, the introduction of the multifractal description in 1980s had an important role in statistical physics, chaos and disordered systems. In particular, to clarify in a rather neat way that the usual idea, coming from critical phenomena, that just few scaling exponents are relevant, is not completely correct, and an infinite set of exponents is necessary for a complete characterization of the scaling features.

In this seminar, the multifractal approach to fully developed turbulence will be discussed, in particular some nontrivial predictions for the statistical properties of the velocity gradients, the existence of an intermediate dissipative range andLagrangian statistics.

The prospect of using the quantum nature of light for long distance quantum communication keeps spurring the search and investigation of suitable sources of entangled photons. Semiconductor quantum dots (QDs), also dubbed “artificial atoms”, are arguably one of the most attractive, as they can generate pairs of polarization-entangled photons with high efficiency and with near-unity degree of entanglement. Despite recent advances, however, the exploitation of photons from QDs in advanced quantum communication protocols remains a major open
challenge.
In this talk, it will be discussed how photons generated by a GaAs quantum dot canbe used to implement quantum teleportation and entanglement swapping protocols with fidelities above the classical limit. Moreover, the first steps towards the construction of a quantum-dot based quantum network for secure communicationwithin the campus of Sapienza University of Rome will be presented. A discussion on future challenges and perspectives will conclude the talk.

The ordinary nuclear matter at high temperature (T> 10¹²K) should undergo a transition to a plasma of quark and gluons, as now predicted by Quantum ChromoDynamics (QCD) at finite temperature. This state of matter that have permeated the first microseconds of the Early Universe can be created for transient of time (10^-22s) in ultra-relativistic heavy-ion collision at RHIC and LHC colliders.

I will overview some basic scales and degrees of freedom of this research area and review some main aspects of this research area emphasizing how over the years it has become possible to “see” inside the created matter probing its substructures at finer and finer scale. In the second part, I will focus the dynamics of the heavy quark in the QGP showing how the first results has shown a strong non-perturbative interaction inducing transport properties in agreement with the expectation from lattice QCD. I will conclude discussing the emerging studies on the impact of the huge initial electromagnetic fields (10¹⁸ Gauss) on their dynamics.