Superplenary lectures (1 hour):
1.- Remo Ruffini (ruffini@icra.it)
Discovery of energy extraction by discrete "Black-Holic" quanta from a Kerr Black Hole in GRB 190114C
Remo Ruffini. (ICRANet / INAF / ICRA)
Almost fifty years after the paper "Introducing the Black Hole" by Ruffini and Wheeler and the Black Hole (BH) mass energy formula by Christodoulou Ruffini and Hawking, we can finally assert that we have been observing the moment of creation of a BH in the BdHN I GRB 190114C with corresponding rotational energy extraction process. The predicted properties of the BdHN I have been now observed: both in this source and in GRB 130427A, in GRB 160509A and in GRB 160625B. The first appearance of the Supernova the SN rise triggering the BdHN has been identified and followed all the way to the appearance of the optical SN. The onset of the GeV radiation coinciding with the BH formation has revealed self similar structures in the time resolved spectral analysis of all sources. Consequently, we find evidence for quantized-discrete-emissions in all sources, with energy quanta of 1037 ergs with repetition time of 10-14 sec. GRBs are the most complex systems ever successfully analyzed in physics and astrophysics, and they may well have a role in the appearance of life in the Cosmos. These results have been made possible by a long-lasting theoretical activity, a comprehensive unprecedented high quality data analysis, an observational multi-messenger effort by the astronomical, the physical and the space research communities. This observational effort is well epitomized by the original Vela Satellites, the NASA Compton space mission (CGRO), the Italo-Dutch Beppo SAX satellite, The Russian Konus Wind Satellite, the NASA Niels-Gehrels SWIFT satellite, the Italian AGILE satellite, the NASA FERMI mission and most recently the Chinese satellite HXMT. These space missions have been assisted by radio and optical equally outstanding observational facilities from the ground.
2.- Sven Reichenberger ( sven.reichenberger@uni-due.de)
Fundamentals, Scalability and Application of Colloidal Metal and Alloy Nanoparticles prepared by Laser Synthesis and Processing in Liquid.
Sven Reichenberger. University of Duisburg-Essen
The presented talk intends to cover the fundamentals of surfactant-free laser-based synthesis hierarchically addressing the role of plasma dynamics, cavitation bubble dynamics and the role of persistent micro bubbles as well as laser properties in this context on the nanoparticle productivity and yielded particle size. The previous will be discussed in terms of noble metal, alloy (here mainly Au, Pd, Pt and related alloys) and oxide nanoparticles. Recent advances in scale-up allowing the g/h-synthesis and post-treatment of nanoparticles, as well as continuous preparation of catalysts up to several 10th of kg per 40h week, will be demonstrated. Finally, newest advances in pulsed laser post-processing and related laser-based defect-engineering of semiconductor and spinel materials, its feasibility and perspectives in fundamental catalytic studies will be discussed.
3.- Andreas Buchleitner (a.buchleitner@physik.uni-freiburg.de)
Quantum transport in complex systems: from single to many particles
Andreas Buchleitner. Albert-Ludwigs-Universitaet Freiburg
While a longstanding subject in different areas of physics, quantum transport in “complex" systems has recently moved back into focus, not least due to remarkable progresses in the experimental characterization and control of multi-component quantum systems. Whereas quantum optics had long followed a strictly reductionist program, with the aim to isolate and control single constituents of matter, we now can witness how “complex" phenomena rapidly emerge as moderate numbers of these constituents are brought together again, at an unprecedented level of control. On a practical level, e.g., entangled states of light are identified as potential information carriers for quantum communication across turbulent media, and multiply connected ensembles of qubits are configured into “prototype quantum computers" which permit nice experimental demonstrations of the actual challenge to control their long-time evolution. This phenomenology raises beautiful theoretical questions with an interest in their own right, such as to which extent “complex" dynamical or transport phenomena can be controlled - at least on a statistical level -, whether robust control can be achieved by exploiting generic and robust features of complex quantum systems, or how targeted performance can be reliably certified, notwithstanding the impossibility of deterministic control or validation as the arguably defining property of truly “complex" quantum systems. Starting out from some by now “historical" examples of “complex" single-particle, the talk will subsequently expand on some current topics in the area of many-particle quantum transport, with an emphasis on the competition between many-particle (in-) distinguishability, interactions, and entanglement, on the one hand, and symmetries and disorder, on the other one.
4.- Heino Falcke (h.falcke@astro.ru.nl):
Imaging Black Holes with the Event Horizon Telescope
Heino Falcke, Radboud University Nijmegen
One of the most fundamental predictions of general relativity are black holes. Their defining feature is the event horizon, the surface that even light cannot escape. When illuminated by ambient light, the event horizon of black holes will cast a dark shadow on the emitting region that is detectable under certain circumstances with global interferometers operating at mm- and submm-wavelengths. Recently the Event Horizon Telescope has detected this shadow feature in the radio galaxy M87, providing a first glimpse at scales surrounding the event horizon. Models invoking general relativity and magnetized plasma hydrodynamics are able to reproduce the appearance of the shadow and of the powerful jet launched at these scales. This provides strong support for the existence of supermassive black holes in the universe and sheds light on how they work. To improve the imaging quality further more telescopes should be added to the array, in particular in Africa. The more distant future will belong to higher frequencies and space-based interferometry. The talk will review the latest results of the Event Horizon Telescope, its scientific implications and future expansions of the array.
5.- Horacio Pastawski (horacio@famaf.unc.edu.ar)
Decoherent Quantum Transport: from Giant Magnetoresistance and SASERs to Quantum Dynamical Phase Transitions
Horacio Pastawski. Universidad Nacional de Córdoba
Quantum conductance in molecular and nano systems at low temperatures becomes well understood through the Landauers motto: “conductance is a transmittance" as calculated from the Schroedinger Equation (SE). However, quantum dynamics is inevitably affected by decoherence which, in turn, becomes critical to recover the macroscopic Ohms law. In spite of this, the few works that include these effects still resort to the early developments that describe the steady-state in terms of the DAmato-Pastawski (DP) model. Its basic idea is that because of the electron-phonon and other interactions with an “environment", an electron loss its memory of its initial state following a Poisson process with a mean-life described by a Fermi Golden Rule (FGR). After each interaction it initiates a \new life". Here, I will show that non-Hermitian Hamiltonians and the Keldysh Greens functions are the natural setting to describe these processes. I describe how Keldysh integral equations become highly simplified for the DP model in a linear response regime consistent with Landauer approach.
The observables are evaluated self-consistently in a discrete space and can be readily generalized to time dependent situations in a multi-terminal settings.
As illustrations for these equations I discuss 1-D model for the Giant Magnetoresistance (GMR). Starting from a quantum description, we recover the standard two resistor model of the GMR. This is achieved by increasing the decoherence controlled by the mean free path and the spin-ip rate, which are Hamiltonian parameters, and determine the observed transport properties. In a device length scale lower than the mean free path, there are interferences that depend on the domain wall size identified with Rabi oscillations. I also discuss a Resonant Tunneling Device where the e-ph scattering processes are considered, within a Fock space description beyond the FGR approximation. This leads to a simple model, which becomes a Floquet Hamiltonian for a classical vibrational field, with antiresonances and resonances in the Fock-Floquet space that describe a phonon laser (SASER). The inclusion of further decoherence processes, besides smoothing out of the resonances, leads to the degradation of the contrast mainly from the suppression of the antiresonances.In a second part, I will show that non-Hermitian Hamiltonians not only imply a trivial exponential decay of quantum memory but could also induce a Quantum Dynamical Phase Transitions as that observed in a SWAP gate. These can be interpreted in terms of spectral bifurcations (exceptional points) in the solutions of the Schroedinger equation, i.e. the complex eigen-energies of the non-Hermitian Hamiltonian. However, quite the dynamical phase transition only shows up in the density described by Keldysh or Lindblad equations, as exceptional points in frequency spectrum, not associated with the energies. I also will explore this situation with a stochastic SE algorithm, the quantum drift (QD), which is a dynamical implementation of the DP model that captures QDPT. As QD involves a single pure wave function that represents the whole thermal ensemble, it is very effective to push the computational limits for decoherent many-body dynamics. Furthermore, by implementing a forward quantum dynamics followed by another one backwards in time and evaluating the Loschmidt Echo, showing that decoherence does not occur uniformly in time but that it is more effective while the state goes through a superposition (entangled) state.
This is consistent with our recent experimental findings that the entangled states are more sensitive to the action of local environments than the simple pointer states. Thus, the extreme sensitivity of the SE of a many-body system to even infinitesimal perturbations, ensures the emergence of the Second Law of Thermodynamics.
