Project acronym 1D-Engine
Project 1D-electrons coupled to dissipation: a novel approach for understanding and engineering superconducting materials and devices
Researcher (PI) Adrian KANTIAN
Host Institution (HI) UPPSALA UNIVERSITET
Call Details Starting Grant (StG), PE3, ERC-2017-STG
Summary Correlated electrons are at the forefront of condensed matter theory. Interacting quasi-1D electrons have seen vast progress in analytical and numerical theory, and thus in fundamental understanding and quantitative prediction. Yet, in the 1D limit fluctuations preclude important technological use, particularly of superconductors. In contrast, high-Tc superconductors in 2D/3D are not precluded by fluctuations, but lack a fundamental theory, making prediction and engineering of their properties, a major goal in physics, very difficult. This project aims to combine the advantages of both areas by making major progress in the theory of quasi-1D electrons coupled to an electron bath, in part building on recent breakthroughs (with the PIs extensive involvement) in simulating 1D and 2D electrons with parallelized density matrix renormalization group (pDMRG) numerics. Such theory will fundamentally advance the study of open electron systems, and show how to use 1D materials as elements of new superconducting (SC) devices and materials: 1) It will enable a new state of matter, 1D electrons with true SC order. Fluctuations from the electronic liquid, such as graphene, could also enable nanoscale wires to appear SC at high temperatures. 2) A new approach for the deliberate engineering of a high-Tc superconductor. In 1D, how electrons pair by repulsive interactions is understood and can be predicted. Stabilization by reservoir - formed by a parallel array of many such 1D systems - offers a superconductor for which all factors setting Tc are known and can be optimized. 3) Many existing superconductors with repulsive electron pairing, all presently not understood, can be cast as 1D electrons coupled to a bath. Developing chain-DMFT theory based on pDMRG will allow these materials SC properties to be simulated and understood for the first time. 4) The insights gained will be translated to 2D superconductors to study how they could be enhanced by contact with electronic liquids.
Summary
Correlated electrons are at the forefront of condensed matter theory. Interacting quasi-1D electrons have seen vast progress in analytical and numerical theory, and thus in fundamental understanding and quantitative prediction. Yet, in the 1D limit fluctuations preclude important technological use, particularly of superconductors. In contrast, high-Tc superconductors in 2D/3D are not precluded by fluctuations, but lack a fundamental theory, making prediction and engineering of their properties, a major goal in physics, very difficult. This project aims to combine the advantages of both areas by making major progress in the theory of quasi-1D electrons coupled to an electron bath, in part building on recent breakthroughs (with the PIs extensive involvement) in simulating 1D and 2D electrons with parallelized density matrix renormalization group (pDMRG) numerics. Such theory will fundamentally advance the study of open electron systems, and show how to use 1D materials as elements of new superconducting (SC) devices and materials: 1) It will enable a new state of matter, 1D electrons with true SC order. Fluctuations from the electronic liquid, such as graphene, could also enable nanoscale wires to appear SC at high temperatures. 2) A new approach for the deliberate engineering of a high-Tc superconductor. In 1D, how electrons pair by repulsive interactions is understood and can be predicted. Stabilization by reservoir - formed by a parallel array of many such 1D systems - offers a superconductor for which all factors setting Tc are known and can be optimized. 3) Many existing superconductors with repulsive electron pairing, all presently not understood, can be cast as 1D electrons coupled to a bath. Developing chain-DMFT theory based on pDMRG will allow these materials SC properties to be simulated and understood for the first time. 4) The insights gained will be translated to 2D superconductors to study how they could be enhanced by contact with electronic liquids.
Max ERC Funding
1 491 013 €
Duration
Start date: 2018-10-01, End date: 2023-09-30
Project acronym 3DMOSHBOND
Project Three-Dimensional Mapping Of a Single Hydrogen Bond
Researcher (PI) Adam Marc SWEETMAN
Host Institution (HI) UNIVERSITY OF LEEDS
Call Details Starting Grant (StG), PE3, ERC-2017-STG
Summary All properties of matter are ultimately governed by the forces between single atoms, but our knowledge of interatomic, and intermolecular, potentials is often derived indirectly.
In 3DMOSHBOND, I outline a program of work designed to create a paradigm shift in the direct measurement of complex interatomic potentials via a fundamental reimagining of how atomic resolution imaging, and force measurement, techniques are applied.
To provide a clear proof of principle demonstration of the power of this concept, I propose to map the strength, shape and extent of single hydrogen bonding (H-bonding) interactions in 3D with sub-Angstrom precision. H-bonding is a key component governing intermolecular interactions, particularly for biologically important molecules. Despite its critical importance, H-bonding is relatively poorly understood, and the IUPAC definition of the H-bond was changed as recently as 2011- highlighting the relevance of a new means to engage with these fundamental interactions.
Hitherto unprecedented resolution and accuracy will be achieved via a creation of a novel layer of vertically oriented H-bonding molecules, functionalisation of the tip of a scanning probe microscope with a single complementary H-bonding molecule, and by complete characterisation of the position of all atoms in the junction. This will place two H-bonding groups “end on” and map the extent, and magnitude, of the H-bond with sub-Angstrom precision for a variety of systems. This investigation of the H-bond will present us with an unparalleled level of information regarding its properties.
Experimental results will be compared with ab initio density functional theory (DFT) simulations, to investigate the extent to which state-of-the-art simulations are able to reproduce the behaviour of the H-bonding interaction. The project will create a new generalised probe for the study of single atomic and molecular interactions.
Summary
All properties of matter are ultimately governed by the forces between single atoms, but our knowledge of interatomic, and intermolecular, potentials is often derived indirectly.
In 3DMOSHBOND, I outline a program of work designed to create a paradigm shift in the direct measurement of complex interatomic potentials via a fundamental reimagining of how atomic resolution imaging, and force measurement, techniques are applied.
To provide a clear proof of principle demonstration of the power of this concept, I propose to map the strength, shape and extent of single hydrogen bonding (H-bonding) interactions in 3D with sub-Angstrom precision. H-bonding is a key component governing intermolecular interactions, particularly for biologically important molecules. Despite its critical importance, H-bonding is relatively poorly understood, and the IUPAC definition of the H-bond was changed as recently as 2011- highlighting the relevance of a new means to engage with these fundamental interactions.
Hitherto unprecedented resolution and accuracy will be achieved via a creation of a novel layer of vertically oriented H-bonding molecules, functionalisation of the tip of a scanning probe microscope with a single complementary H-bonding molecule, and by complete characterisation of the position of all atoms in the junction. This will place two H-bonding groups “end on” and map the extent, and magnitude, of the H-bond with sub-Angstrom precision for a variety of systems. This investigation of the H-bond will present us with an unparalleled level of information regarding its properties.
Experimental results will be compared with ab initio density functional theory (DFT) simulations, to investigate the extent to which state-of-the-art simulations are able to reproduce the behaviour of the H-bonding interaction. The project will create a new generalised probe for the study of single atomic and molecular interactions.
Max ERC Funding
1 971 468 €
Duration
Start date: 2018-01-01, End date: 2022-12-31
Project acronym ADMIRE
Project Atomic-scale Design of Majorana states and their Innovative Real-space Exploration
Researcher (PI) Roland WIESENDANGER
Host Institution (HI) UNIVERSITAET HAMBURG
Call Details Advanced Grant (AdG), PE3, ERC-2017-ADG
Summary Fault-tolerant topological quantum computation has become one of the most exciting research directions in modern condensed matter physics. As a key operation the braiding of non-Abelian anyons has been proposed theoretically. Such exotic quasiparticles can be realized as zero-energy Majorana bound states at the ends of one-dimensional magnetic nanowires in proximity to s-wave superconductors in the presence of high spin-orbit coupling. In contrast to previous attempts to realize such systems experimentally, based on the growth of semiconducting nanowires or the self-assembly of ferromagnetic nanowires on s-wave superconductors, we propose to design Majorana bound states in artificially constructed single-atom chains with non-collinear spin-textures on elemental superconducting substrates using scanning tunnelling microscope (STM)-based atom manipulation techniques. We would like to study at the atomic level the formation of Shiba bands as a result of hybridization of individual Shiba impurity states as well as the emergence of zero-energy Majorana bound states as a function of chain structure, length, and composition. Moreover, we will construct model-type platforms, such as T-junctions, rings, and more complex network structures with atomic-scale precision as a basis for demonstrating the manipulation and braiding of Majorana bound states. We will make use of sophisticated experimental techniques, such as spin-resolved scanning tunnelling spectroscopy (STS) at micro-eV energy resolution, scanning Josephson tunnelling spectroscopy, and multi-probe STS under well-defined ultra-high vacuum conditions, in order to directly probe the nature of the magnetic state of the atomic wires, the spin-polarization of the emergent Majorana states, as well as the spatial nature of the superconducting order parameter in real space. Finally, we will try to directly probe the quantum exchange statistics of non-Abelian anyons in these atomically precise fabricated model-type systems.
Summary
Fault-tolerant topological quantum computation has become one of the most exciting research directions in modern condensed matter physics. As a key operation the braiding of non-Abelian anyons has been proposed theoretically. Such exotic quasiparticles can be realized as zero-energy Majorana bound states at the ends of one-dimensional magnetic nanowires in proximity to s-wave superconductors in the presence of high spin-orbit coupling. In contrast to previous attempts to realize such systems experimentally, based on the growth of semiconducting nanowires or the self-assembly of ferromagnetic nanowires on s-wave superconductors, we propose to design Majorana bound states in artificially constructed single-atom chains with non-collinear spin-textures on elemental superconducting substrates using scanning tunnelling microscope (STM)-based atom manipulation techniques. We would like to study at the atomic level the formation of Shiba bands as a result of hybridization of individual Shiba impurity states as well as the emergence of zero-energy Majorana bound states as a function of chain structure, length, and composition. Moreover, we will construct model-type platforms, such as T-junctions, rings, and more complex network structures with atomic-scale precision as a basis for demonstrating the manipulation and braiding of Majorana bound states. We will make use of sophisticated experimental techniques, such as spin-resolved scanning tunnelling spectroscopy (STS) at micro-eV energy resolution, scanning Josephson tunnelling spectroscopy, and multi-probe STS under well-defined ultra-high vacuum conditions, in order to directly probe the nature of the magnetic state of the atomic wires, the spin-polarization of the emergent Majorana states, as well as the spatial nature of the superconducting order parameter in real space. Finally, we will try to directly probe the quantum exchange statistics of non-Abelian anyons in these atomically precise fabricated model-type systems.
Max ERC Funding
2 499 750 €
Duration
Start date: 2019-01-01, End date: 2023-12-31
Project acronym APOGEE
Project Atomic-scale physics of single-photon sources.
Researcher (PI) GUILLAUME ARTHUR FRANCOIS SCHULL
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Consolidator Grant (CoG), PE3, ERC-2017-COG
Summary Single-photon sources (SPSs) are systems capable of emitting photons one by one. These sources are of major importance for quantum-information science and applications. SPSs experiments generally rely on the optical excitation of two level systems of atomic-scale dimensions (single-molecules, vacancies in diamond…). Many fundamental questions related to the nature of these sources and the impact of their environment remain to be explored:
Can SPSs be addressed with atomic-scale spatial accuracy? How do the nanometer-scale distance or the orientation between two (or more) SPSs affect their emission properties? Does coherence emerge from the proximity between the sources? Do these structures still behave as SPSs or do they lead to the emission of correlated photons? How can we then control the degree of entanglement between the sources? Can we remotely excite the emission of these sources by using molecular chains as charge-carrying wires? Can we couple SPSs embodied in one or two-dimensional arrays? How does mechanical stress or localised plasmons affect the properties of an electrically-driven SPS?
Answering these questions requires probing, manipulating and exciting SPSs with an atomic-scale precision. This is beyond what is attainable with an all-optical method. Since they can be confined to atomic-scale pathways we propose to use electrons rather than photons to excite the SPSs. This unconventional approach provides a direct access to the atomic-scale physics of SPSs and is relevant for the implementation of these sources in hybrid devices combining electronic and photonic components. To this end, a scanning probe microscope will be developed that provides simultaneous spatial, chemical, spectral, and temporal resolutions. Single-molecules and defects in monolayer transition metal dichalcogenides are SPSs that will be studied in the project, and which are respectively of interest for fundamental and more applied issues.
Summary
Single-photon sources (SPSs) are systems capable of emitting photons one by one. These sources are of major importance for quantum-information science and applications. SPSs experiments generally rely on the optical excitation of two level systems of atomic-scale dimensions (single-molecules, vacancies in diamond…). Many fundamental questions related to the nature of these sources and the impact of their environment remain to be explored:
Can SPSs be addressed with atomic-scale spatial accuracy? How do the nanometer-scale distance or the orientation between two (or more) SPSs affect their emission properties? Does coherence emerge from the proximity between the sources? Do these structures still behave as SPSs or do they lead to the emission of correlated photons? How can we then control the degree of entanglement between the sources? Can we remotely excite the emission of these sources by using molecular chains as charge-carrying wires? Can we couple SPSs embodied in one or two-dimensional arrays? How does mechanical stress or localised plasmons affect the properties of an electrically-driven SPS?
Answering these questions requires probing, manipulating and exciting SPSs with an atomic-scale precision. This is beyond what is attainable with an all-optical method. Since they can be confined to atomic-scale pathways we propose to use electrons rather than photons to excite the SPSs. This unconventional approach provides a direct access to the atomic-scale physics of SPSs and is relevant for the implementation of these sources in hybrid devices combining electronic and photonic components. To this end, a scanning probe microscope will be developed that provides simultaneous spatial, chemical, spectral, and temporal resolutions. Single-molecules and defects in monolayer transition metal dichalcogenides are SPSs that will be studied in the project, and which are respectively of interest for fundamental and more applied issues.
Max ERC Funding
1 996 848 €
Duration
Start date: 2018-06-01, End date: 2023-05-31
Project acronym CASTLES
Project Charge And Spin in TopologicaL Edge States
Researcher (PI) ERWANN YANN EMILE BOCQUILLON
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Starting Grant (StG), PE3, ERC-2017-STG
Summary Topology provides mathematical tools to sort objects according to global properties regardless of local details, and manifests itself in various fields of physics. In solid-state physics, specific topological properties of the band structure, such as a band inversion, can for example robustly enforce the appearance of spin-polarized conducting states at the boundaries of the material, while its bulk remains insulating. The boundary states of these ‘topological insulators’ in fact provide a support system to encode information non-locally in ‘topological quantum bits’ robust to local perturbations. The emerging ‘topological quantum computation’ is as such an envisioned solution to decoherence problems in the realization of quantum computers. Despite immense theoretical and experimental efforts, the rise of these new materials has however been hampered by strong difficulties to observe robust and clear signatures of their predicted properties such as spin-polarization or perfect conductance.
These challenges strongly motivate my proposal to study two-dimensional topological insulators, and in particular explore the unknown dynamics of their topological edge states in normal and superconducting regimes. First it is possible to capture information both on charge and spin dynamics, and more clearly highlight the basic properties of topological edge states. Second, the dynamics reveals the effects of Coulomb interactions, an unexplored aspect that may explain the fragility of topological edge states. Finally, it enables the manipulation and characterization of quantum states on short time scales, relevant to quantum information processing. This project relies on the powerful toolbox offered by radiofrequency and current-correlations techniques and promises to open a new field of dynamical explorations of topological materials.
Summary
Topology provides mathematical tools to sort objects according to global properties regardless of local details, and manifests itself in various fields of physics. In solid-state physics, specific topological properties of the band structure, such as a band inversion, can for example robustly enforce the appearance of spin-polarized conducting states at the boundaries of the material, while its bulk remains insulating. The boundary states of these ‘topological insulators’ in fact provide a support system to encode information non-locally in ‘topological quantum bits’ robust to local perturbations. The emerging ‘topological quantum computation’ is as such an envisioned solution to decoherence problems in the realization of quantum computers. Despite immense theoretical and experimental efforts, the rise of these new materials has however been hampered by strong difficulties to observe robust and clear signatures of their predicted properties such as spin-polarization or perfect conductance.
These challenges strongly motivate my proposal to study two-dimensional topological insulators, and in particular explore the unknown dynamics of their topological edge states in normal and superconducting regimes. First it is possible to capture information both on charge and spin dynamics, and more clearly highlight the basic properties of topological edge states. Second, the dynamics reveals the effects of Coulomb interactions, an unexplored aspect that may explain the fragility of topological edge states. Finally, it enables the manipulation and characterization of quantum states on short time scales, relevant to quantum information processing. This project relies on the powerful toolbox offered by radiofrequency and current-correlations techniques and promises to open a new field of dynamical explorations of topological materials.
Max ERC Funding
1 499 940 €
Duration
Start date: 2018-02-01, End date: 2023-01-31
Project acronym DarkSERS
Project Harvesting dark plasmons for surface-enhanced Raman scattering
Researcher (PI) Stephanie REICH
Host Institution (HI) FREIE UNIVERSITAET BERLIN
Call Details Consolidator Grant (CoG), PE3, ERC-2017-COG
Summary Metal nanostructures show pronounced electromagnetic resonances that arise from localized surface plasmons. These collective oscillations of free electrons in the metal give rise to confined electromagnetic near fields. Surface-enhanced spectroscopy exploits the near-field intensity to enhance the optical response of nanomaterials by many orders of magnitude.
Plasmons are classified as bright and dark depending on their interaction with far-field radiation. Bright modes are dipole-allowed excitations that absorb and scatter light. Dark modes are resonances of the electromagnetic near field only that do not couple to propagating modes. The suppressed photon emission of dark plasmons makes their resonances spectrally narrow and intense, which is highly desirable for enhanced spectroscopy as well as storing and transporting electromagnetic energy in nanostructures. The suppressed absorption, however, prevents us from routinely exploiting dark modes in nanoplasmonic systems.
I propose using spatially patterned light beams to excite dark plasmons with far-field radiation. By this I mean a beam profile with varying polarization and intensity that will be matched to the dark electromagnetic eigenmode. My approach activates the excitation of dark modes, while their radiative decay remains suppressed. I will show how to harvest dark modes for surface-enhanced Raman scattering providing superior intensity and an enhancement that is tailored to a specific vibration. Another feature of dark modes is their strong coupling to the vibrations of nanostructures. I will use this to amplify vibrational modes and, ultimately, induce phonon lasing.
The proposed research aims at an enabling technology that unlocks a novel range of nanoplasmonic properties. It will put dark plasmons on par with the well-recognized bright modes to be used in fundamental science and for applications in analytics, optoelectronic, and nanoimaging.
Summary
Metal nanostructures show pronounced electromagnetic resonances that arise from localized surface plasmons. These collective oscillations of free electrons in the metal give rise to confined electromagnetic near fields. Surface-enhanced spectroscopy exploits the near-field intensity to enhance the optical response of nanomaterials by many orders of magnitude.
Plasmons are classified as bright and dark depending on their interaction with far-field radiation. Bright modes are dipole-allowed excitations that absorb and scatter light. Dark modes are resonances of the electromagnetic near field only that do not couple to propagating modes. The suppressed photon emission of dark plasmons makes their resonances spectrally narrow and intense, which is highly desirable for enhanced spectroscopy as well as storing and transporting electromagnetic energy in nanostructures. The suppressed absorption, however, prevents us from routinely exploiting dark modes in nanoplasmonic systems.
I propose using spatially patterned light beams to excite dark plasmons with far-field radiation. By this I mean a beam profile with varying polarization and intensity that will be matched to the dark electromagnetic eigenmode. My approach activates the excitation of dark modes, while their radiative decay remains suppressed. I will show how to harvest dark modes for surface-enhanced Raman scattering providing superior intensity and an enhancement that is tailored to a specific vibration. Another feature of dark modes is their strong coupling to the vibrations of nanostructures. I will use this to amplify vibrational modes and, ultimately, induce phonon lasing.
The proposed research aims at an enabling technology that unlocks a novel range of nanoplasmonic properties. It will put dark plasmons on par with the well-recognized bright modes to be used in fundamental science and for applications in analytics, optoelectronic, and nanoimaging.
Max ERC Funding
2 299 506 €
Duration
Start date: 2018-04-01, End date: 2023-03-31
Project acronym DYNACQM
Project Dynamics of Correlated Quantum Matter: From Dynamical Probes to Novel Phases of Matter
Researcher (PI) Frank POLLMANN
Host Institution (HI) TECHNISCHE UNIVERSITAET MUENCHEN
Call Details Consolidator Grant (CoG), PE3, ERC-2017-COG
Summary The interplay of quantum fluctuations and correlation effects in condensed matter can yield emergent phases with fascinating properties. Understanding these challenging quantum-many body systems is a problem of central importance in theoretical physics and the basis for the development of new materials for future technologies. Dynamical properties can provide characteristic fingerprints that allow to identify novel phases in newly synthesized materials and optical lattice systems. Moreover, when brought out of equilibrium, correlated quantum matter can exhibit dynamical phases that cannot occur in equilibrium settings.
DYNACQM will develop new theoretical and numerical frameworks to study dynamical properties of correlated quantum matter. On the theoretical side, we will investigate how many-body entanglement affects dynamical properties and predict universal features that can be measured in experiments. For example, dynamical spin correlation functions, measured in neutron scattering experiments, provide signatures of topologically ordered spin liquids. Furthermore, we will study the role of disorder and many-body localization in static as well as in driven quantum systems. On the numerical side, we will develop efficient tensor-product state based algorithms to simulate the dynamics of quantum many-body systems. These will allow us to study realistic microscopic model systems and to understand their dynamical properties.
Recent developments in the creation of synthetic quantum systems and advances in high resolution spectroscopy allow for an unprecedented precision with which the dynamics of quantum systems can be studied and manipulated experimentally. In this light, it is particularly important to theoretically understand the dynamics of correlated quantum systems and to make testable predictions. DYNACQM will bridge between the fundamental understanding of many-body entanglement in correlated quantum matter and experiments.
Summary
The interplay of quantum fluctuations and correlation effects in condensed matter can yield emergent phases with fascinating properties. Understanding these challenging quantum-many body systems is a problem of central importance in theoretical physics and the basis for the development of new materials for future technologies. Dynamical properties can provide characteristic fingerprints that allow to identify novel phases in newly synthesized materials and optical lattice systems. Moreover, when brought out of equilibrium, correlated quantum matter can exhibit dynamical phases that cannot occur in equilibrium settings.
DYNACQM will develop new theoretical and numerical frameworks to study dynamical properties of correlated quantum matter. On the theoretical side, we will investigate how many-body entanglement affects dynamical properties and predict universal features that can be measured in experiments. For example, dynamical spin correlation functions, measured in neutron scattering experiments, provide signatures of topologically ordered spin liquids. Furthermore, we will study the role of disorder and many-body localization in static as well as in driven quantum systems. On the numerical side, we will develop efficient tensor-product state based algorithms to simulate the dynamics of quantum many-body systems. These will allow us to study realistic microscopic model systems and to understand their dynamical properties.
Recent developments in the creation of synthetic quantum systems and advances in high resolution spectroscopy allow for an unprecedented precision with which the dynamics of quantum systems can be studied and manipulated experimentally. In this light, it is particularly important to theoretically understand the dynamics of correlated quantum systems and to make testable predictions. DYNACQM will bridge between the fundamental understanding of many-body entanglement in correlated quantum matter and experiments.
Max ERC Funding
1 998 750 €
Duration
Start date: 2018-06-01, End date: 2023-05-31
Project acronym E-DESIGN
Project Artificial designer materials
Researcher (PI) Peter LILJEROTH
Host Institution (HI) AALTO KORKEAKOULUSAATIO SR
Call Details Advanced Grant (AdG), PE3, ERC-2017-ADG
Summary Constructing designer materials where the atomic geometry, interactions, magnetism and other relevant parameters can be precisely controlled is becoming reality. I will reach this aim by positioning every atom with the tip of a scanning probe microscope, or by using molecular self-assembly to reach the desired structures. I will realize and engineer several novel quantum materials hosting exotic electronic phases: 2D topological insulators in metal-organic frameworks (MOF) and 2D topological superconductors in hybrid molecule-superconductor structures. These classes of materials have not yet been experimentally realized but could enable novel spintronic and quantum computing devices. In addition, we will realize a tuneable platform for quantum simulation in solid-state artificial lattices, which could open a whole new area in this field.
I will employ a broad experimental approach to reach the above targets by utilizing molecular self-assembly and scanning probe microscopy -based atom/molecule manipulation. The systems are characterized using low-temperature atomic force microscopy (AFM) and scanning tunneling microscopy (STM). My group is one of the leading groups in these topics globally. We have initial results on the topics discussed in this proposal and are thus in a unique position to make ground-breaking contributions in realizing designer quantum materials.
The artificial designer materials we study are characterized by the engineered electronic response with atomically precise geometries, lattice symmetries and controlled interactions. Such ingredients can result in ultimately controllable materials that have large, robust and quick responses to small stimuli with applications in nanoelectronics, flexible electronics, high-selectivity and high-sensitivity sensors, and optoelectronic components. Longer term, the biggest impact is expected through a profound change in the way we view materials and what can be achieved through designer materials approach.
Summary
Constructing designer materials where the atomic geometry, interactions, magnetism and other relevant parameters can be precisely controlled is becoming reality. I will reach this aim by positioning every atom with the tip of a scanning probe microscope, or by using molecular self-assembly to reach the desired structures. I will realize and engineer several novel quantum materials hosting exotic electronic phases: 2D topological insulators in metal-organic frameworks (MOF) and 2D topological superconductors in hybrid molecule-superconductor structures. These classes of materials have not yet been experimentally realized but could enable novel spintronic and quantum computing devices. In addition, we will realize a tuneable platform for quantum simulation in solid-state artificial lattices, which could open a whole new area in this field.
I will employ a broad experimental approach to reach the above targets by utilizing molecular self-assembly and scanning probe microscopy -based atom/molecule manipulation. The systems are characterized using low-temperature atomic force microscopy (AFM) and scanning tunneling microscopy (STM). My group is one of the leading groups in these topics globally. We have initial results on the topics discussed in this proposal and are thus in a unique position to make ground-breaking contributions in realizing designer quantum materials.
The artificial designer materials we study are characterized by the engineered electronic response with atomically precise geometries, lattice symmetries and controlled interactions. Such ingredients can result in ultimately controllable materials that have large, robust and quick responses to small stimuli with applications in nanoelectronics, flexible electronics, high-selectivity and high-sensitivity sensors, and optoelectronic components. Longer term, the biggest impact is expected through a profound change in the way we view materials and what can be achieved through designer materials approach.
Max ERC Funding
2 374 922 €
Duration
Start date: 2018-09-01, End date: 2023-08-31
Project acronym eNANO
Project FREE ELECTRONS AS ULTRAFAST NANOSCALE PROBES
Researcher (PI) Javier Garcia de Abajo
Host Institution (HI) FUNDACIO INSTITUT DE CIENCIES FOTONIQUES
Call Details Advanced Grant (AdG), PE3, ERC-2017-ADG
Summary With eNANO I will introduce a disruptive approach toward controlling and understanding the dynamical response of material nanostructures, expanding nanoscience and nanotechnology in unprecedented directions. Specifically, I intend to inaugurate the field of free-electron nanoelectronics, whereby electrons evolving in the vacuum regions defined by nanostructures will be generated, guided, and sampled at the nanoscale, thus acting as probes to excite, detect, image, and spectrally resolve polaritonic modes (e.g., plasmons, optical phonons, and excitons) with atomic precision over sub-femtosecond timescales. I will exploit the wave nature of electrons, extending the principles of nanophotonics from photons to electrons, therefore gaining in spatial resolution (by relying on the large reduction in wavelength) and strength of interaction (mediated by Coulomb fields, which in contrast to photons render nonlinear interactions ubiquitous when using free electrons). I will develop the theoretical and computational tools required to investigate this unexplored scenario, covering a wide range of free-electron energies, their elastic interactions with the material atomic structures, and their inelastic coupling to nanoscale dynamical excitations. Equipped with these techniques, I will further address four challenges of major scientific interest: (i) the fundamental limits to the space, time, and energy resolutions achievable with free electrons; (ii) the foundations and feasibility of pump-probe spectral microscopy at the single-electron level; (iii) the exploration of quantum-optics phenomena by means of free electrons; and (iv) the unique perspectives and potential offered by vertically confined free-electrons in 2D crystals. I will face these research frontiers by combining knowledge from different areas through a multidisciplinary theory group, in close collaboration with leading experimentalists, pursuing a radically new approach to study and control the nanoworld.
Summary
With eNANO I will introduce a disruptive approach toward controlling and understanding the dynamical response of material nanostructures, expanding nanoscience and nanotechnology in unprecedented directions. Specifically, I intend to inaugurate the field of free-electron nanoelectronics, whereby electrons evolving in the vacuum regions defined by nanostructures will be generated, guided, and sampled at the nanoscale, thus acting as probes to excite, detect, image, and spectrally resolve polaritonic modes (e.g., plasmons, optical phonons, and excitons) with atomic precision over sub-femtosecond timescales. I will exploit the wave nature of electrons, extending the principles of nanophotonics from photons to electrons, therefore gaining in spatial resolution (by relying on the large reduction in wavelength) and strength of interaction (mediated by Coulomb fields, which in contrast to photons render nonlinear interactions ubiquitous when using free electrons). I will develop the theoretical and computational tools required to investigate this unexplored scenario, covering a wide range of free-electron energies, their elastic interactions with the material atomic structures, and their inelastic coupling to nanoscale dynamical excitations. Equipped with these techniques, I will further address four challenges of major scientific interest: (i) the fundamental limits to the space, time, and energy resolutions achievable with free electrons; (ii) the foundations and feasibility of pump-probe spectral microscopy at the single-electron level; (iii) the exploration of quantum-optics phenomena by means of free electrons; and (iv) the unique perspectives and potential offered by vertically confined free-electrons in 2D crystals. I will face these research frontiers by combining knowledge from different areas through a multidisciplinary theory group, in close collaboration with leading experimentalists, pursuing a radically new approach to study and control the nanoworld.
Max ERC Funding
1 899 788 €
Duration
Start date: 2018-12-01, End date: 2023-11-30
Project acronym EQFT
Project Emergence from Quantum Frustration and Topology
Researcher (PI) Radu COLDEA
Host Institution (HI) THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD
Call Details Advanced Grant (AdG), PE3, ERC-2017-ADG
Summary Highly-correlated many-body quantum states often emerge from correlations between strongly interacting electrons. The proposed research will experimentally explore emergent properties of quantum materials in the presence of strong correlations and spin-orbit coupling, when the spin and orbital angular momentum of electrons are strongly entangled. This is a largely experimentally unexplored regime where theoretical guidance suggests a fertile ground to potentially discover completely new types of correlated quantum behaviour, ranging from quantum spin liquids, where a local spin flip creates multiple exotic quasiparticles with fractional quantum numbers, to novel forms of magnetic order, with counter-rotating spin spirals or spontaneously formed periodic arrangements of spin vortices, to magnetic quasiparticles with topological properties. High applied magnetic fields will be used to stabilize novel magnetic phases with the potential to discover new universality classes for field-driven quantum phase transitions. Single crystals of spin-orbit dominated quantum materials, with key ingredients to exhibit correlated quantum behaviour, will be synthesized and their magnetic states will be probed using the latest advances in neutron and resonant x-ray diffraction and spectroscopy techniques that allow unprecedented high-sensitivity mapping of the static and dynamic correlations in space and time (or momentum and energy). The results will be compared with the latest theoretical models of many-body correlated quantum states with spin-orbit entanglement. This research will establish the experimental manifestation and manipulation of magnetic quasiparticles with topological character and help build a systematic understanding of the organizing principles that govern emergent quantum phases of matter in the unexplored regime of strong correlations and spin-orbit entanglement.
Summary
Highly-correlated many-body quantum states often emerge from correlations between strongly interacting electrons. The proposed research will experimentally explore emergent properties of quantum materials in the presence of strong correlations and spin-orbit coupling, when the spin and orbital angular momentum of electrons are strongly entangled. This is a largely experimentally unexplored regime where theoretical guidance suggests a fertile ground to potentially discover completely new types of correlated quantum behaviour, ranging from quantum spin liquids, where a local spin flip creates multiple exotic quasiparticles with fractional quantum numbers, to novel forms of magnetic order, with counter-rotating spin spirals or spontaneously formed periodic arrangements of spin vortices, to magnetic quasiparticles with topological properties. High applied magnetic fields will be used to stabilize novel magnetic phases with the potential to discover new universality classes for field-driven quantum phase transitions. Single crystals of spin-orbit dominated quantum materials, with key ingredients to exhibit correlated quantum behaviour, will be synthesized and their magnetic states will be probed using the latest advances in neutron and resonant x-ray diffraction and spectroscopy techniques that allow unprecedented high-sensitivity mapping of the static and dynamic correlations in space and time (or momentum and energy). The results will be compared with the latest theoretical models of many-body correlated quantum states with spin-orbit entanglement. This research will establish the experimental manifestation and manipulation of magnetic quasiparticles with topological character and help build a systematic understanding of the organizing principles that govern emergent quantum phases of matter in the unexplored regime of strong correlations and spin-orbit entanglement.
Max ERC Funding
2 500 000 €
Duration
Start date: 2018-10-01, End date: 2023-09-30