Project acronym 3D-FM
Project Taking Force Microscopy into the Third Dimension
Researcher (PI) Tjerk Hendrik Oosterkamp
Host Institution (HI) UNIVERSITEIT LEIDEN
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary I propose to pursue two emerging Force Microscopy techniques that allow measuring structural properties below the surface of the specimen. Whereas Force Microscopy (most commonly known under the name AFM) is usually limited to measuring the surface topography and surface properties of a specimen, I will demonstrate that Force Microscopy can achieve true 3D images of the structure of the cell nucleus. In Ultrasound Force Microscopy, an ultrasound wave is launched from below towards the surface of the specimen. After the sound waves interact with structures beneath the surface of the specimen, the local variations in the amplitude and phase shift of the ultrasonic surface motion is collected by the Force Microscopy tip. Previously, measured 2D maps of the surface response have shown that the surface response is sensitive to structures below the surface. In this project I will employ miniature AFM cantilevers and nanotube tips that I have already developed in my lab. This will allow me to quickly acquire many such 2D maps at a much wider range of ultrasound frequencies and from these 2D maps calculate the full 3D structure below the surface. I expect this technique to have a resolving power better than 10 nm in three dimensions as far as 2 microns below the surface. In parallel I will introduce a major improvement to a technique based on Nuclear Magnetic Resonance (NMR). Magnetic Resonance Force Microscopy measures the interaction of a rotating nuclear spin in the field gradient of a magnetic Force Microscopy tip. However, these forces are so small that they pose an enormous challenge. Miniature cantilevers and nanotube tips, in combination with additional innovations in the detection of the cantilever motion, can overcome this problem. I expect to be able to measure the combined signal of 100 proton spins or fewer, which will allow me to measure proton densities with a resolution of 5 nm, but possibly even with atomic resolution.
Summary
I propose to pursue two emerging Force Microscopy techniques that allow measuring structural properties below the surface of the specimen. Whereas Force Microscopy (most commonly known under the name AFM) is usually limited to measuring the surface topography and surface properties of a specimen, I will demonstrate that Force Microscopy can achieve true 3D images of the structure of the cell nucleus. In Ultrasound Force Microscopy, an ultrasound wave is launched from below towards the surface of the specimen. After the sound waves interact with structures beneath the surface of the specimen, the local variations in the amplitude and phase shift of the ultrasonic surface motion is collected by the Force Microscopy tip. Previously, measured 2D maps of the surface response have shown that the surface response is sensitive to structures below the surface. In this project I will employ miniature AFM cantilevers and nanotube tips that I have already developed in my lab. This will allow me to quickly acquire many such 2D maps at a much wider range of ultrasound frequencies and from these 2D maps calculate the full 3D structure below the surface. I expect this technique to have a resolving power better than 10 nm in three dimensions as far as 2 microns below the surface. In parallel I will introduce a major improvement to a technique based on Nuclear Magnetic Resonance (NMR). Magnetic Resonance Force Microscopy measures the interaction of a rotating nuclear spin in the field gradient of a magnetic Force Microscopy tip. However, these forces are so small that they pose an enormous challenge. Miniature cantilevers and nanotube tips, in combination with additional innovations in the detection of the cantilever motion, can overcome this problem. I expect to be able to measure the combined signal of 100 proton spins or fewer, which will allow me to measure proton densities with a resolution of 5 nm, but possibly even with atomic resolution.
Max ERC Funding
1 794 960 €
Duration
Start date: 2008-08-01, End date: 2013-07-31
Project acronym BIOSELFORGANIZATION
Project Biophysical aspects of self-organization in actin-based cell motility
Researcher (PI) Kinneret Magda Keren
Host Institution (HI) TECHNION - ISRAEL INSTITUTE OF TECHNOLOGY
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary Cell motility is a fascinating dynamic process crucial for a wide variety of biological phenomena including defense against injury or infection, embryogenesis and cancer metastasis. A spatially extended, self-organized, mechanochemical machine consisting of numerous actin polymers, accessory proteins and molecular motors drives this process. This impressive assembly self-organizes over several orders of magnitude in both the temporal and spatial domains bridging from the fast dynamics of individual molecular-sized building blocks to the persistent motion of whole cells over minutes and hours. The molecular players involved in the process and the basic biochemical mechanisms are largely known. However, the principles governing the assembly of the motility apparatus, which involve an intricate interplay between biophysical processes and biochemical reactions, are still poorly understood. The proposed research is focused on investigating the biophysical aspects of the self-organization processes underlying cell motility and trying to adapt these processes to instill motility in artificial cells. Important biophysical characteristics of moving cells such as the intracellular fluid flow and membrane tension will be measured and their effect on the motility process will be examined, using fish epithelial keratocytes as a model system. The dynamics of the system will be further investigated by quantitatively analyzing the morphological and kinematic variation displayed by a population of cells and by an individual cell through time. Such measurements will feed into and direct the development of quantitative theoretical models. In parallel, I will work toward the development of a synthetic physical model system for cell motility by encapsulating the actin machinery in a cell-sized compartment. This synthetic system will allow cell motility to be studied in a simplified and controlled environment, detached from the complexity of the living cell.
Summary
Cell motility is a fascinating dynamic process crucial for a wide variety of biological phenomena including defense against injury or infection, embryogenesis and cancer metastasis. A spatially extended, self-organized, mechanochemical machine consisting of numerous actin polymers, accessory proteins and molecular motors drives this process. This impressive assembly self-organizes over several orders of magnitude in both the temporal and spatial domains bridging from the fast dynamics of individual molecular-sized building blocks to the persistent motion of whole cells over minutes and hours. The molecular players involved in the process and the basic biochemical mechanisms are largely known. However, the principles governing the assembly of the motility apparatus, which involve an intricate interplay between biophysical processes and biochemical reactions, are still poorly understood. The proposed research is focused on investigating the biophysical aspects of the self-organization processes underlying cell motility and trying to adapt these processes to instill motility in artificial cells. Important biophysical characteristics of moving cells such as the intracellular fluid flow and membrane tension will be measured and their effect on the motility process will be examined, using fish epithelial keratocytes as a model system. The dynamics of the system will be further investigated by quantitatively analyzing the morphological and kinematic variation displayed by a population of cells and by an individual cell through time. Such measurements will feed into and direct the development of quantitative theoretical models. In parallel, I will work toward the development of a synthetic physical model system for cell motility by encapsulating the actin machinery in a cell-sized compartment. This synthetic system will allow cell motility to be studied in a simplified and controlled environment, detached from the complexity of the living cell.
Max ERC Funding
900 000 €
Duration
Start date: 2008-08-01, End date: 2013-07-31
Project acronym BISMUTH
Project Breaking Inversion Symmetry in Magnets: Understand via THeory
Researcher (PI) Silvia Picozzi
Host Institution (HI) CONSIGLIO NAZIONALE DELLE RICERCHE
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary 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
Summary
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
Max ERC Funding
684 000 €
Duration
Start date: 2008-05-01, End date: 2012-04-30
Project acronym CEESC
Project Control of entangled electron spins on a chip
Researcher (PI) Lieven Mark Koenraad Vandersypen
Host Institution (HI) TECHNISCHE UNIVERSITEIT DELFT
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary The promise of nanoscience stems from the fundamentally new behavior that emerges at the nanoscale. Here, we propose to explore, control and exploit one of the most dramatic aspects of this unusual behavior: quantum entanglement of spins. Our nanoscale system of choice is an array of semiconductor quantum dots that each contain one single electron. Thanks to a string of recent breakthroughs, it is now possible to initialize, coherently manipulate and read out the spin state of one such electron, and to couple it coherently to a spin in a neighboring dot. Today, we are at the brink of a new era in this field, in which entanglement will play the central part. The primary goal of this proposal, therefore, is to experimentally demonstrate that electron spins in quantum dots can really be entangled, and to control this entanglement in time. We will then use this capability to implement various quantum information protocols such as quantum algorithms and teleportation, which intrinsically rely on entanglement to realize tasks that are classically impossible. In order to push the level of coherent control to its limits, we will suppress fluctuations in the normally uncontrolled spin environment, and pursue novel quantum dot technologies which offer an intrinsically ‘quiet’ environment. Our long-term dream is to demonstrate that the accuracy threshold for fault-tolerant quantum computation can be reached in this system, which would permit quantum coherence and entanglement to be preserved indefinitely. This research is presently very much at the stage of exploratory research and is bound to produce surprising and unexpected outcomes. Furthermore, we are convinced that pushing the frontier of quantum control in nanoscale devices has a real potential to lead to future quantum technologies.
Summary
The promise of nanoscience stems from the fundamentally new behavior that emerges at the nanoscale. Here, we propose to explore, control and exploit one of the most dramatic aspects of this unusual behavior: quantum entanglement of spins. Our nanoscale system of choice is an array of semiconductor quantum dots that each contain one single electron. Thanks to a string of recent breakthroughs, it is now possible to initialize, coherently manipulate and read out the spin state of one such electron, and to couple it coherently to a spin in a neighboring dot. Today, we are at the brink of a new era in this field, in which entanglement will play the central part. The primary goal of this proposal, therefore, is to experimentally demonstrate that electron spins in quantum dots can really be entangled, and to control this entanglement in time. We will then use this capability to implement various quantum information protocols such as quantum algorithms and teleportation, which intrinsically rely on entanglement to realize tasks that are classically impossible. In order to push the level of coherent control to its limits, we will suppress fluctuations in the normally uncontrolled spin environment, and pursue novel quantum dot technologies which offer an intrinsically ‘quiet’ environment. Our long-term dream is to demonstrate that the accuracy threshold for fault-tolerant quantum computation can be reached in this system, which would permit quantum coherence and entanglement to be preserved indefinitely. This research is presently very much at the stage of exploratory research and is bound to produce surprising and unexpected outcomes. Furthermore, we are convinced that pushing the frontier of quantum control in nanoscale devices has a real potential to lead to future quantum technologies.
Max ERC Funding
1 296 000 €
Duration
Start date: 2008-07-01, End date: 2013-06-30
Project acronym COMOSYEL
Project Complex Molecular-scale Systems for NanoElectronics and NanoPlasmonics
Researcher (PI) Erik Dujardin
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary COMOSYEL aims at designing complex nanometric and molecular systems to process electronic or optical information from the macroscopic to the molecular scale. It proposes two specific, unconventional approaches to molecular electronics and plasmonics and the development of two multidisciplinary technical toolkits, one in bio-inspired chemistry and one in surface nanopatterning by liquid nanodispensing that will support the first two topics, and eventually become a part of the team's culture for future research developments. (1) Graphene-based nanoelectronics is an experimental implementation of mono-molecular electronics concept using graphene to bridge the macroscopic world to the molecular scale. This topic aims at encoding and processing electronic information in a single complex molecular system in order to achieve complex logic functions. (2) Self-assembled nanoplasmonics aims at developing a molecular plasmonics concept. Here, complex networks of sub-20nm crystalline metallic nanoparticle chains are produced and interfaced to convert photons to plasmons and ultimately confine, enhance and route light energy from a conventional light source to an arbitrary chromophore on a substrate. (3) Bio-inspired nanomaterials chemistry will be the main synthetic tool to produce new multifunctional nanostructured materials able to address and collect information from/to the macroscopic world to/from the single molecule level. Both morphogenesis and self-assembly will be explored to better control size and shape of nano-objects and the topology of higher-order architectures. (4) Liquid nanodispensing is a promising tool to interface nanosized/molecular sized systems with both lithographically produced host structures and individual molecular systems. A nanoscale liquid dispensing technique derived from AFM combines resolution and versatility and will be pushed to its extreme to master the deposition of nanoobjects onto a substrate or a precise modification of surfaces.
Summary
COMOSYEL aims at designing complex nanometric and molecular systems to process electronic or optical information from the macroscopic to the molecular scale. It proposes two specific, unconventional approaches to molecular electronics and plasmonics and the development of two multidisciplinary technical toolkits, one in bio-inspired chemistry and one in surface nanopatterning by liquid nanodispensing that will support the first two topics, and eventually become a part of the team's culture for future research developments. (1) Graphene-based nanoelectronics is an experimental implementation of mono-molecular electronics concept using graphene to bridge the macroscopic world to the molecular scale. This topic aims at encoding and processing electronic information in a single complex molecular system in order to achieve complex logic functions. (2) Self-assembled nanoplasmonics aims at developing a molecular plasmonics concept. Here, complex networks of sub-20nm crystalline metallic nanoparticle chains are produced and interfaced to convert photons to plasmons and ultimately confine, enhance and route light energy from a conventional light source to an arbitrary chromophore on a substrate. (3) Bio-inspired nanomaterials chemistry will be the main synthetic tool to produce new multifunctional nanostructured materials able to address and collect information from/to the macroscopic world to/from the single molecule level. Both morphogenesis and self-assembly will be explored to better control size and shape of nano-objects and the topology of higher-order architectures. (4) Liquid nanodispensing is a promising tool to interface nanosized/molecular sized systems with both lithographically produced host structures and individual molecular systems. A nanoscale liquid dispensing technique derived from AFM combines resolution and versatility and will be pushed to its extreme to master the deposition of nanoobjects onto a substrate or a precise modification of surfaces.
Max ERC Funding
1 439 712 €
Duration
Start date: 2008-08-01, End date: 2013-12-31
Project acronym COSPSENA
Project Coherence of Spins in Semiconductor Nanostructures
Researcher (PI) Dominik Max Zumbühl
Host Institution (HI) UNIVERSITAT BASEL
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary Macroscopic control of quantum states is a major theme in much of modern physics because quantum coherence enables study of fundamental physics and has promising applications for quantum information processing. The potential significance of quantum computing is recognized well beyond the physics community. For electron spins in GaAs quantum dots, it has become clear that decoherence caused by interactions with the nuclear spins is a major challenge. We propose to investigate and reduce hyperfine induced decoherence with two complementary approaches: nuclear spin state narrowing and nuclear spin polarization. We propose a new projective state narrowing technique: a large, Coulomb blockaded dot measures the qubit nuclear ensemble, resulting in enhanced spin coherence times. Further, mediated by an interacting 2D electron gas via hyperfine interaction, a low temperature nuclear ferromagnetic spin state was predicted, which we propose to investigate using a quantum point contact as a nuclear polarization detector. Estimates indicate that the nuclear ferromagnetic transition occurs in the sub-Millikelvin range, well below already hard to reach temperatures around 10 mK. However, the exciting combination of interacting electron and nuclear spin physics as well as applications in spin qubits give ample incentive to strive for sub-Millikelvin temperatures in nanostructures. We propose to build a novel type of nuclear demagnetization refrigerator aiming to reach electron temperatures of 0.1 mK in semiconductor nanostructures. This interdisciplinary project combines Microkelvin and nanophysics, going well beyond the status quo. It is a challenging project that could be the beginning of a new era of coherent spin physics with unprecedented quantum control. This project requires a several year commitment and a team of two graduate students plus one postdoctoral fellow.
Summary
Macroscopic control of quantum states is a major theme in much of modern physics because quantum coherence enables study of fundamental physics and has promising applications for quantum information processing. The potential significance of quantum computing is recognized well beyond the physics community. For electron spins in GaAs quantum dots, it has become clear that decoherence caused by interactions with the nuclear spins is a major challenge. We propose to investigate and reduce hyperfine induced decoherence with two complementary approaches: nuclear spin state narrowing and nuclear spin polarization. We propose a new projective state narrowing technique: a large, Coulomb blockaded dot measures the qubit nuclear ensemble, resulting in enhanced spin coherence times. Further, mediated by an interacting 2D electron gas via hyperfine interaction, a low temperature nuclear ferromagnetic spin state was predicted, which we propose to investigate using a quantum point contact as a nuclear polarization detector. Estimates indicate that the nuclear ferromagnetic transition occurs in the sub-Millikelvin range, well below already hard to reach temperatures around 10 mK. However, the exciting combination of interacting electron and nuclear spin physics as well as applications in spin qubits give ample incentive to strive for sub-Millikelvin temperatures in nanostructures. We propose to build a novel type of nuclear demagnetization refrigerator aiming to reach electron temperatures of 0.1 mK in semiconductor nanostructures. This interdisciplinary project combines Microkelvin and nanophysics, going well beyond the status quo. It is a challenging project that could be the beginning of a new era of coherent spin physics with unprecedented quantum control. This project requires a several year commitment and a team of two graduate students plus one postdoctoral fellow.
Max ERC Funding
1 377 000 €
Duration
Start date: 2008-06-01, End date: 2013-05-31
Project acronym FEMTOSCOPY
Project Femtosecond Raman Spectroscopy: ultrafast transformations in physics, chemistry and biology
Researcher (PI) Tullio Scopigno
Host Institution (HI) UNIVERSITA DEGLI STUDI DI ROMA LA SAPIENZA
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary 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.
Summary
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.
Max ERC Funding
1 544 400 €
Duration
Start date: 2008-09-01, End date: 2013-08-31
Project acronym GRAPHENE
Project Physics and Applications of Graphene
Researcher (PI) Konstantin Novoselov
Host Institution (HI) THE UNIVERSITY OF MANCHESTER
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary This proposal is based on the PI’s recent work in which a conceptually new class of materials – two dimensional atomic crystals – was discovered. Such crystals can be seen as individual atomic planes “pulled out” of bulk crystals and were previously presumed not to exist in the free state. Despite being only one atom thick and unprotected from the immediate environment, these materials can be extremely stable. The PI’s work has focused on graphene, a freestanding monolayer of graphite where carbon atoms are densely packed in a honeycomb lattice. Due to its high quality and unique electronic spectrum (electrons in graphene mimic relativistic quantum particles called Dirac fermions), graphene has become a gold mine for searching for new phenomena. Graphene also offers numerous applications from smart materials to future electronics. The general objective of the proposal is to exploit the PI’s current lead in the emerging research area, so that no opportunity is missed to find new effects that are expected to be abundant in graphene, and to exploit possible applications. The project will cover three main directions, exploring most exciting features about graphene. First, the PI is planning to concentrate on graphene membranes and investigate properties induced by the unique dimensionality of these one atom thick objects. Second, charge carriers in graphene mimic massless relativistic particles, and this exceptional property allows access to the rich and subtle physics of quantum electrodynamics in a bench-top condensed matter experiment. To this end, interaction and many-body effects will be investigated. Third, graphene is considered to be a realistic candidate for electronics beyond the Si age, and one of the priorities of this project will be studies of graphene-based transistor applications. All these research directions combined should create a solid basis for a new internationally-leading research laboratory led by the PI.
Summary
This proposal is based on the PI’s recent work in which a conceptually new class of materials – two dimensional atomic crystals – was discovered. Such crystals can be seen as individual atomic planes “pulled out” of bulk crystals and were previously presumed not to exist in the free state. Despite being only one atom thick and unprotected from the immediate environment, these materials can be extremely stable. The PI’s work has focused on graphene, a freestanding monolayer of graphite where carbon atoms are densely packed in a honeycomb lattice. Due to its high quality and unique electronic spectrum (electrons in graphene mimic relativistic quantum particles called Dirac fermions), graphene has become a gold mine for searching for new phenomena. Graphene also offers numerous applications from smart materials to future electronics. The general objective of the proposal is to exploit the PI’s current lead in the emerging research area, so that no opportunity is missed to find new effects that are expected to be abundant in graphene, and to exploit possible applications. The project will cover three main directions, exploring most exciting features about graphene. First, the PI is planning to concentrate on graphene membranes and investigate properties induced by the unique dimensionality of these one atom thick objects. Second, charge carriers in graphene mimic massless relativistic particles, and this exceptional property allows access to the rich and subtle physics of quantum electrodynamics in a bench-top condensed matter experiment. To this end, interaction and many-body effects will be investigated. Third, graphene is considered to be a realistic candidate for electronics beyond the Si age, and one of the priorities of this project will be studies of graphene-based transistor applications. All these research directions combined should create a solid basis for a new internationally-leading research laboratory led by the PI.
Max ERC Funding
1 775 044 €
Duration
Start date: 2008-12-01, End date: 2013-10-31
Project acronym LASER-ARPES
Project Laser based photoemission: revolutionizing the spectroscopy of correlated electrons
Researcher (PI) Felix Baumberger
Host Institution (HI) UNIVERSITE DE GENEVE
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary It is proposed to develop a novel instrument for angular resolved photoelectron spectroscopy (ARPES) by combining a laser based ultraviolet light source with a state-of-the-art electron spectrometer. This combination will be unique in Europe and will push this important technique to an entirely new level of resolution, comparable to the thermal broadening at 1 K and nearly an order of magnitude lower than the resolution achievable in practical ARPES experiments with the latest synchrotron light sources. The low photon energy of this new source will also markedly enhance the bulk sensitivity of ARPES and thus enable the investigation of interesting materials that were not accessible so far. These new capabilities will be used to study the subtle quantum many-body states of correlated electrons in transition metal oxides, a frontier topic in condensed-matter physics. Specifically, we will focus on electronic instabilities in perovskites and elucidate how different degrees of freedom play together to determine the often vastly different properties of chemically closely related materials. Moreover, we will apply modern electron spectroscopy to correlated molecular solids with complex phase diagrams that challenge existing theory for satisfactory explanations. This field is largely unexplored but is fundamental for advances in molecular electronics.
Summary
It is proposed to develop a novel instrument for angular resolved photoelectron spectroscopy (ARPES) by combining a laser based ultraviolet light source with a state-of-the-art electron spectrometer. This combination will be unique in Europe and will push this important technique to an entirely new level of resolution, comparable to the thermal broadening at 1 K and nearly an order of magnitude lower than the resolution achievable in practical ARPES experiments with the latest synchrotron light sources. The low photon energy of this new source will also markedly enhance the bulk sensitivity of ARPES and thus enable the investigation of interesting materials that were not accessible so far. These new capabilities will be used to study the subtle quantum many-body states of correlated electrons in transition metal oxides, a frontier topic in condensed-matter physics. Specifically, we will focus on electronic instabilities in perovskites and elucidate how different degrees of freedom play together to determine the often vastly different properties of chemically closely related materials. Moreover, we will apply modern electron spectroscopy to correlated molecular solids with complex phase diagrams that challenge existing theory for satisfactory explanations. This field is largely unexplored but is fundamental for advances in molecular electronics.
Max ERC Funding
1 450 825 €
Duration
Start date: 2008-08-01, End date: 2013-07-31
Project acronym MASPIC
Project Spin currents in magnetic nanostructures
Researcher (PI) Mathias Kläui
Host Institution (HI) JOHANNES GUTENBERG-UNIVERSITAT MAINZ
Call Details Starting Grant (StG), PE3, ERC-2007-StG
Summary MaSpic will create an autonomous team at the University of Konstanz to investigate the interaction between magnetization, spin - polarized and pure diffusive spin currents using novel instrumentation and innovative theoretical approaches. A thorough understanding of the fundamental charge and spin transport interaction mechanisms, key to use of the spin degree of freedom for Spintronics, will be developed. To understand the interplay between spin-polarized charge currents and magnetization configurations (adiabatic vs. non-adiabatic electron transport), the reciprocal effects of magnetization on the current (magnetoresistance) and of the current on magnetization (spin transfer torque) will be correlated for the same spin structures. Non-intrusive high resolution imaging at variable temperature will be used to probe the non-adiabaticity and help understand the hotly debated influence of thermal excitations on transport. Pure diffusive spin currents will be efficiently generated and used to manipulate magnetization with ultra-low power dissipation. The poorly understood spin current generation by the Spin Hall Effect and spin current propagation will be probed by direct imaging and the sign of the spin accumulation and influence of scattering determined to separate intrinsic and extrinsic effects. For the measurements a unique variable temperature high resolution SEMPA imaging system will be acquired and further developed including ultra-fast electrical contacts. Theoretical modelling using an atomistic Heisenberg approach will go beyond the conventional micromagnetic calculations that are limited to 0K. To understand thermal transport effects, temperature dependent simulations with adiabatic and non-adiabatic spin torque terms will accompany experiments. Realistic lattice structures and heterostructures will be modelled to simulate the influence of the pure spin currents on the magnetization using spatially varying interface torque terms, not previously possible.
Summary
MaSpic will create an autonomous team at the University of Konstanz to investigate the interaction between magnetization, spin - polarized and pure diffusive spin currents using novel instrumentation and innovative theoretical approaches. A thorough understanding of the fundamental charge and spin transport interaction mechanisms, key to use of the spin degree of freedom for Spintronics, will be developed. To understand the interplay between spin-polarized charge currents and magnetization configurations (adiabatic vs. non-adiabatic electron transport), the reciprocal effects of magnetization on the current (magnetoresistance) and of the current on magnetization (spin transfer torque) will be correlated for the same spin structures. Non-intrusive high resolution imaging at variable temperature will be used to probe the non-adiabaticity and help understand the hotly debated influence of thermal excitations on transport. Pure diffusive spin currents will be efficiently generated and used to manipulate magnetization with ultra-low power dissipation. The poorly understood spin current generation by the Spin Hall Effect and spin current propagation will be probed by direct imaging and the sign of the spin accumulation and influence of scattering determined to separate intrinsic and extrinsic effects. For the measurements a unique variable temperature high resolution SEMPA imaging system will be acquired and further developed including ultra-fast electrical contacts. Theoretical modelling using an atomistic Heisenberg approach will go beyond the conventional micromagnetic calculations that are limited to 0K. To understand thermal transport effects, temperature dependent simulations with adiabatic and non-adiabatic spin torque terms will accompany experiments. Realistic lattice structures and heterostructures will be modelled to simulate the influence of the pure spin currents on the magnetization using spatially varying interface torque terms, not previously possible.
Max ERC Funding
1 610 786 €
Duration
Start date: 2008-08-01, End date: 2014-04-30
