The Wigner function [1] is a quantum mechanical distribution function and lives in phase space. It allows us to evaluate the expectation values of symmetrically ordered operators. Moreover, it is an extremely useful tool [2] to analyze phenomena at the interface of classical and quantum physics. In the present talk, we focus on three such topics: (i) The equivalence principle of general...
A hundred years ago, the sun-Earth connection was of interest to only a small number of scientists. Solar activity had little effect on daily life. Today, a single strong solar eruption could bring civilization to its knees. Modern society has come to depend on technologies sensitive to solar radiation and geomagnetic storms. Particularly vulnerable are power grids, interplanetary robotic and...
One of the most remarkable possibilities of General Relativity concerns gravitational collapse to black holes, leaving behind a geometry with light rings, ergoregions and horizons. These peculiarities are responsible for uniqueness properties and energy extraction mechanisms that turn black holes into ideal laboratories of strong gravity, of particle physics (yes!) and of possible...
Measurements at the frontier of particle physics performed by the LHC experiments have been a great success when considering the discovery of the Higgs boson. This was an important missing piece in the puzzle of the standard model that governs particle interactions. However, all other measurements have not provided results incompatible with this theory, thus showing no pointer towards...
Shortly, milliseconds after the Big Bang, the Universe was formed of a dense and hot matter, the quark gluon plasma. The properties of this strongly interacting medium set the initial condition of the expansion of the Universe later on. Heavy-ion researchers aim to address the questions: How this matter look like? What are the physical properties of this state? Can we re-create this matter in...
The Quantum Information National Laboratory (QNL) boosts the research and development activity of the Hungarian scientific community within the unfolding second quantum revolution which aims at the exploitation of the enormous advancements in our ability to detect and manipulate single quanta for new kinds of applications. We give an overview on the QNL activity via selected outstanding...
Experiments on strongly coupled dusty plasmas provide unique access to the microscopic details of macroscopic condensed matter processes. Since the early years of this field, the application to hydrodynamic processes has been one of the main motivations. In most cases, however, the complexity of the experiments prevented the drawing of general conclusions. In our experiment, using the control...
When a granular material or a suspension containing elongated particles is flowing we observe that the particles get aligned. This is due to the non-trivial rotation of the grains in a shear flow. How long does it take for the grains to get ordered? In which direction do they align? What is the consequence of ordering on the rheology? Do elongated particles flow easier than spherical ones? In...
I will review two recent techniques for cosmological N-body simulations. The StePS simulations use a stereographic projection to compactify the universe and fit it into a finite computer. The resulting multiresolution technique is more efficient than standard zoom-in simulations and has isotropic gravity. Complementary simulations augment an existing simulation by minimizing cosmic variance by...
For visible light, the concept of spectrographic imaging — dispersion of
radiation components with various energies in space — has been known since
Newton’s time. In this presentation, we report on a hard (14 keV) x-ray
spectrograph implemented at the European synchrotron, enabling an
observation of anomalous soft modes in alpha-iron [1]. We present new
unpublished data on temperature...
Recently, FeRh thin films have attracted extensive attention, due to the diversity of their possible applications [[i]]. Their near room temperature metamagnetic transition from antiferromagnetic (AF) to ferromagnetic (FM) order [[ii],] and the interoperability between FM and paramagnetic (PM) states provide an excellent base for energy-saving spintronic devices [[iii]]. Moreover, the...
Detection of genuine quantum correlations, such as entanglement or steerability, by local quantum measurements, which can possibly be performed by far distant observers, are of particular interest for applications in quantum key distribution and quantum communication.
In this context the natural question arises how does the effectiveness of detecting such genuine quantum correlations depend...
Symmetries play a fundamental role in physics: from conservation laws and the unification of different theories to the simplification of complex problems to tractable ones. They are an indispensable tool and continue to be a driving force in research. This talk explores two topics from Quantum Information Science that places symmetry, and
therefore group theory, in the spotlight. First, the...
A linear response of quantum electrons is well studied and for that well developed theoretical and computational methods computing the linear response properties are available. However, recent introduction of THz lasers and the novel seeding technique to reach high intensities [1] allow us to generate nonlinear response of quantum electrons in extended systems. Therefore, in this talk the...
Scattering near-field optical microscopy (s-SNOM), based on the combination of atomic
force microscopy and frequency-dependent light scattering, is an emerging method that combines high spatial resolution with high sensitivity even at long illuminating wavelengths.
I will present results in the infrared frequency range obtained on various aspects of carbon nanostructures. The most...
Our department is currently participating in several leading international space research projects to study and analyze in situ measurements taken in the solar wind and in the vicinity of various solar system objects. Our expertise reaches back to the 1980's, when our collaboration with the international space agencies first began. Ever since then we have been active in the scientific data...
Driven-dissipative systems are characterized by the appearance of steady-states. Upon parameter change, they can undergo dissipative phase transitions between different types of steady-states. One of the paradigmatic examples for a first order dissipative phase transition is the driven nonlinear single-mode optical resonator. I will report on the corresponding realization within an ultracold...
I present the relatively recent concept of first-order dissipative phase transitions that can occur in meso- and even microscopic quantum systems. One of the first examples of this phenomenology was the photon-blockade breakdown (PBB) effect, that occurs most simply in a coupled system of a bosonic mode and a qubit. For PBB, an abstract thermodynamic limit has been identified [1], where the...
Nitrogen-vacancy (NV) centers in diamond enable a variety of sensing applications ranging from measuring basic properties, such as temperature, pressure, strain, and external fields, down to detecting single cells, single molecules, or even single nuclear spins. Here, we present new opportunities for quantum sensing with shallow NV centers, i.e. located within 10 nm from the surface. First, we...
Recently, ambitious goals have been phrased on how technology can boost or heal brain function, focussing on concerted hardware developments. In this talk I will present how developments in Artificial Intelligence research enables us to gain deeper insight into how neurons contribute to cognitive functions.
Here we report an extended study for the creation of smart porous nanomaterials, including all three porosity regimes (micro-meso and macro porosity) via 3 distinct (and tunable) templating strategies. The idea is to synthesize a novel multi-modal porous scaffold with high surface areas where the hierarchical porosity would provide a vascular and open network of porosity. To achieve this we...
