ERC FUNDED PROJECTS

Multiferroics (i.e. materials where ferroelectricity and magnetism coexist) are presently drawing enormous interests, due to their technologically-relevant multifunctional character and to the astoundingly rich playground for fundamental condensed-matter physics they constitute. Here, we put forward several concepts on how to break inversion symmetry and achieve sizable ferroelectricity in collinear magnets; our approach is corroborated via first-principles calculations as tools to quantitatively estimate relevant ferroelectric and magnetic properties as well as to reveal ab-initio the main mechanisms behind the dipolar and magnetic orders. In closer detail, we focus on the interplay between ferroelectricity and electronic degrees of freedom in magnets, i.e. on those cases where spin- or orbital- or charge-ordering can be the driving force for a spontaneous polarization to develop. Antiferromagnetism will be considered as a primary mechanism for lifting inversion symmetry; however, the effects of charge disproportionation and orbital ordering will also be studied by examining a wide class of materials, including ortho-manganites with E-type spin-arrangement, non-E-type antiferromagnets, nickelates, etc. Finally, as an example of materials-design accessible to our ab-initio approach, we use “chemistry” to break inversion symmetry by artificially constructing an oxide superlattice and propose a way to switch, via an electric field, from antiferromagnetism to ferrimagnetism. To our knowledge, the link between electronic degrees of freedom and ferroelectricity in collinear magnets is an almost totally unexplored field by ab-initio methods; indeed, its clear understanding and optimization would lead to a scientific breakthrough in the multiferroics area. Technologically, it would pave the way to materials design of magnetic ferroelectrics with properties persisting above room temperature and, therefore, to a novel generation of electrically-controlled spintronic devices

684 000 €

Start date: 2008-05-01, End date: 2012-04-30

The project is aimed at funding a multi-disciplinary laboratory on nonlinear optics and photonics in soft-colloidal materials and on “complex lightwave systems”. A team of talented young researchers, divided among experiments, theory, parallel computation and nano-fabrication is involved. The proposed research will foster several breakthrough discoveries from soft-matter to biophysics, from nonlinear and integrated optics to the science of complexity and cryptography. The underlying vision is driven by the physics of complex systems, those displaying a large number of thermodynamically equivalent states and emergent properties. There are 4 original and high-impact activities, which explore applicative potentialities: 1) sub-wavelength light filaments in soft- and bio-matter; 2) lasers in soft-matter and bio-tissues; 3) control of soft-matter lasers by light filaments; 4) complex lightwave systems, encryption by nano-structured disordered lasers. Activity 1 will lead to ultra-thin re-addressable light beams (sub-wavelength spatial solitons) propagating in soft- and bio-matter that can be used in laser-surgery, matter manipulation and able to guide high power laser pulses; activity 2 attains novel structural diagnostic techniques in bone tissue surpassing limits of nuclear magnetic resonance imaging, and assesses the field of lasers in soft-materials; activity 3 will demonstrate the control of self-organization processes in soft-matter by light filaments probed by laser emission; activity 4 is based on specific features mutuated from spin-glass theory, and will realize a novel cryptographic technique superior to chaotic systems in terms of security. Activity 1 and 2 are propaedeutic to the others. The team is composed by the Principal Investigator (P.I.), 4 post-doctoral researchers and 3 Ph.D. students. The budget will be used for paying the P.I., two post-doctoral positions, laser sources, high performance computing facilities, and instrumentation.

1 085 000 €

Start date: 2008-05-01, End date: 2013-04-30

First principles Density-Functional Theory (DFT) methods have been widely applied for computing electronic and optical properties of different systems. Recently theoretical modeling of metal-organic interfaces received a much attention due to their importance in different nanoscience fields. However, common (i.e. local and semi-local) approximations to the exchange-correlation (XC) functional of DFT show several shortcomings in describing metal-organic energy-levels alignment and thus charge-transfer. Aim of the DEDOM (DEvelopment of Density functional theory methods for Organic Metal interaction) project is to elaborate new theoretical methods beyond the current state-of-the-art for the description of the electronic and optical properties of organic molecules linked or deposited on metal surfaces or metal nanoparticles. This task includes: i) the development of new and efficient XC functionals, based on optimized effective potential (OEP) and including exact-exchange and correlation from many-body theory, to obtain an accurate description of charge-transfer between organic molecules and metal surfaces; ii) the investigation of optical properties, including light-emission, of organic molecules on metal surfaces using Time-Dependent DFT; iii) the description of metals using Green’s functions and multi-scale approaches to investigate metal-induced modification of the optical properties of organic molecules, including fluorescence quenching or enhancement due to the coupling of electronic excitations to plasmons. The DEDOM project is theoretically and technically extremely challenging due to the use of unconventional orbital-dependent XC-functionals and it requires a strong interdisciplinary effort, joining solid-state physics, theoretical chemistry, electromagnetic engineering and implementation of advanced computational techniques. If successful, it will represent a major progress in the theoretical description of organic-metal interfaces.

1 250 000 €

Start date: 2008-07-01, End date: 2013-12-31

We propose the construction and development of a femtosecond broadband stimulated Raman setup to tackle ultra fast chemical, physical and biological processes taking advantage of the top-notch structural sensitivity inherent to the Raman process. The use of a pump-probe stimulated scheme will allow to overcome time-energy restrictions dictated by the uncertainty principle, enabling to reach the femtosecond timescale with energy resolutions which would pertain to the picosecond time domain in the Heisenberg sense. Protein dynamics span several orders of magnitude extending up to macroscopic timescales, the recipes to tailor properties of rubbers and polymers relevant for human timescales are covered by more than 500000 patents, rust reaction occurs over several days, and lethal brain strokes often lead to death within 24 hours on average. The lowest hierarchical level of such processes, however, is hidden in the very act of atomic motion and chemical binding such as the single bond dynamics in a peptide backbone, the monomer cross-linking elemental reactions, the energy flow and re-distribution in a hydrogen bond network, or the oxygen binding to heme proteins, all performing on the femtosecond stage. Mastering these processes is the essence of femtochemistry, born around the backbone of the femtosecond laser technology and boosted by scientific activity which led to the Nobel prize of Prof. A. Zewail in 1999. The new capabilities offered by femtosecond sources have often left behind in the race traditional spectroscopies, which hardly follow the growing emergence of new challenging problems in which the traditional distinction between biology, chemistry and physics is smeared out by the common ultra short timescale. The set up of a non conventional femtosecond Raman technique will be the initiating event for the establishment of a research group of interdisciplinary nature toiling over unsolved problems in which the ultrafast facet plays a key role.

1 544 400 €

Start date: 2008-09-01, End date: 2013-08-31