ERC FUNDED PROJECTS

Light is one of today’s most powerful tools for exploriLight is one of today’s most powerful tools for exploring nature at the frontier of the human knowledge. The rapid development of laser technology allow us today to generate ultrashort pulses of coherent structured light: light fields with custom spatial and temporal properties, such as intensity, phase and angular momentum. The later one represents one of the most interesting light properties nowadays, as topological light beams carrying angular momentum interact with matter differently, introducing mechanical motion to micro and nano-structures, and affecting fundamental excitation rules. High-order harmonic generation (HHG) stands as a unique mechanism to provide coherent flashes of light with outstanding properties: its radiation spectrum expands from the vacuum ultraviolet to the soft x-rays; it can be synthesized in pulses as short as several attoseconds (10^-18 seconds): and it can be structured in its angular momentum properties. This proposal represents a timely opportunity to explore the ground-breaking opportunities offered by attosecond structured x-ray sources. It conveys computing light-matter interaction in extreme conditions, which requires an extraordinary effort in the elaboration of new theoretical tools to design, propose and guide future experiments at the frontier of ultrafast science. We shall pioneer the new scenario of angular momenta in structured ultrashort x-rays –the most complex coherent pulses to date–. It is not difficult to envision a new era in ultrafast nanotechnology that makes use of these x-ray sources. In particular we shall pioneer their application to nanoscience and ultrafast magnetism. We aim to establish the grounding principles of attomagnetism, taking advantage of the unique opportunity offered by structured light pulses to induce pure attosecond magnetic fields, which could set the precedents of high-rate magnetic recording through ultrafast magnetization reversal.

1 425 000 €

Start date: 2020-03-01, End date: 2025-02-28

Given a quantum system, how can one ensure that it (i) is entangled? (ii) random? (iii) secure? (iv) performs a computation correctly? The concept of quantum certification embraces all these questions and CERQUTE’s main goal is to provide the tools to achieve such certification. The need of a new paradigm for quantum certification has emerged as a consequence of the impressive advances on the control of quantum systems. On the one hand, complex many-body quantum systems are prepared in many labs worldwide. On the other hand, quantum information technologies are making the transition to real applications. Quantum certification is a highly transversal concept that covers a broad range of scenarios –from many-body systems to protocols employing few devices– and questions –from theoretical results and experimental demonstrations to commercial products–. CERQUTE is organized along three research lines that reflect this broadness and inter-disciplinary character: (A) many-body quantum systems: the objective is to provide the tools to identify quantum properties of many-body quantum systems; (B) quantum networks: the objective is to characterize networks in the quantum regime; (C) quantum cryptographic protocols: the objective is to construct cryptography protocols offering certified security. Crucial to achieve these objectives is the development of radically new methods to deal with quantum systems in an efficient way. Expected outcomes are: (i) new methods to detect quantum phenomena in the many-body regime, (ii) new protocols to benchmark quantum simulators and annealers, (iii) first methods to characterize quantum causality, (iv) new protocols exploiting simple network geometries (v) experimentally-friendly cryptographic protocols offering certified security. CERQUTE goes at the heart of the fundamental question of what distinguishes quantum from classical physics and will provide the concepts and protocols for the certification of quantum phenomena and technologies.

1 735 044 €

Start date: 2020-01-01, End date: 2024-12-31

During the last decade, quantum entanglement has been intensively studied within quantum information science and has also appeared as a natural goal of recent quantum experiments. Because of that the theoretical background of detecting entanglement has been rapidly developing. However, most of this development concentrated on bipartite or few-party entanglement, while today's experiments typically involve many particles. Thus, as one of the most interesting part of quantum optics and quantum information, I chose to study multi-partite entanglement theory, with a stress on creation and generation of many-particle entanglement. There are two main system types in today's experiments. In some systems all particles are individually accessible, such as trapped ions or photons. In such systems entanglement detection is still a challenge as the number of local measurements is limited. I propose to study efficient methods for detecting entanglement in such systems. In other physical systems, such as cold ensembles of a million atoms, particles are not accessible individually and only collective measurements are possible. To obtain useful information about the quantum state is a challenge. I propose to study entanglement creation and detection also in such systems. The latter topic is naturally connected to the efficient modeling of large quantum systems, since exact modeling is not possible for such system sizes.

1 294 350 €

Start date: 2011-03-01, End date: 2017-02-28

With the advent of the Large Hadron Collider (LHC), particle and nuclear physics have entered a new era. Heavy ion collisions at the LHC have already begun to provide new insights into the quark-gluon plasma (QGP) phase of Quantum Chromodynamics (QCD). The beam energy scan program at the Relativistic Heavy Ion Collider (RHIC) will explore part of the rich phase diagram of QCD at finite baryon density. Proton-proton collisions at the LHC will uncover the mechanism responsible for electroweak symmetry breaking (EWSB). Much of the physics involved in these experiments is, or may turn out to be, strongly coupled. Making contact with experiment thus requires a theoretical understanding of strongly coupled gauge dynamics. This project aims at using the gauge/string duality to make essential contributions to our understanding of: (i) Out-of-equilbrium dynamics of the QGP, in particular of the thermalization process; (ii) The QCD phase diagram, in particular of color superconducting phases; (iii) Strongly coupled dynamics potentially relevant for EWSB, in particular of walking dynamics. These three main objectives are interconnected by two horizontal lines: (i) Identification of universal observables, which hold the best potential to make contact with experiment, and (ii) Communication with other fields, which is crucial for the success of such an interdisciplinary proposal.

1 419 424 €

Start date: 2012-10-01, End date: 2017-09-30