Project acronym ANYONIC
Project Statistics of Exotic Fractional Hall States
Researcher (PI) Mordehai HEIBLUM
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Advanced Grant (AdG), PE3, ERC-2018-ADG
Summary Since their discovery, Quantum Hall Effects have unfolded intriguing avenues of research, exhibiting a multitude of unexpected exotic states: accurate quantized conductance states; particle-like and hole-conjugate fractional states; counter-propagating charge and neutral edge modes; and fractionally charged quasiparticles - abelian and (predicted) non-abelian. Since the sought-after anyonic statistics of fractional states is yet to be verified, I propose to launch a thorough search for it employing new means. I believe that our studies will serve the expanding field of the emerging family of topological materials.
Our on-going attempts to observe quasiparticles (qp’s) interference, in order to uncover their exchange statistics (under ERC), taught us that spontaneous, non-topological, ‘neutral edge modes’ are the main culprit responsible for qp’s dephasing. In an effort to quench the neutral modes, we plan to develop a new class of micro-size interferometers, based on synthetically engineered fractional modes. Flowing away from the fixed physical edge, their local environment can be controlled, making it less hospitable for the neutral modes.
Having at hand our synthetized helical-type fractional modes, it is highly tempting to employ them to form localize para-fermions, which will extend the family of exotic states. This can be done by proximitizing them to a superconductor, or gapping them via inter-mode coupling.
The less familiar thermal conductance measurements, which we recently developed (under ERC), will be applied throughout our work to identify ‘topological orders’ of exotic states; namely, distinguishing between abelian and non-abelian fractional states.
The proposal is based on an intensive and continuous MBE effort, aimed at developing extremely high purity, GaAs based, structures. Among them, structures that support our new synthetic modes that are amenable to manipulation, and others that host rare exotic states, such as v=5/2, 12/5, 19/8, and 35/16.
Summary
Since their discovery, Quantum Hall Effects have unfolded intriguing avenues of research, exhibiting a multitude of unexpected exotic states: accurate quantized conductance states; particle-like and hole-conjugate fractional states; counter-propagating charge and neutral edge modes; and fractionally charged quasiparticles - abelian and (predicted) non-abelian. Since the sought-after anyonic statistics of fractional states is yet to be verified, I propose to launch a thorough search for it employing new means. I believe that our studies will serve the expanding field of the emerging family of topological materials.
Our on-going attempts to observe quasiparticles (qp’s) interference, in order to uncover their exchange statistics (under ERC), taught us that spontaneous, non-topological, ‘neutral edge modes’ are the main culprit responsible for qp’s dephasing. In an effort to quench the neutral modes, we plan to develop a new class of micro-size interferometers, based on synthetically engineered fractional modes. Flowing away from the fixed physical edge, their local environment can be controlled, making it less hospitable for the neutral modes.
Having at hand our synthetized helical-type fractional modes, it is highly tempting to employ them to form localize para-fermions, which will extend the family of exotic states. This can be done by proximitizing them to a superconductor, or gapping them via inter-mode coupling.
The less familiar thermal conductance measurements, which we recently developed (under ERC), will be applied throughout our work to identify ‘topological orders’ of exotic states; namely, distinguishing between abelian and non-abelian fractional states.
The proposal is based on an intensive and continuous MBE effort, aimed at developing extremely high purity, GaAs based, structures. Among them, structures that support our new synthetic modes that are amenable to manipulation, and others that host rare exotic states, such as v=5/2, 12/5, 19/8, and 35/16.
Max ERC Funding
1 801 094 €
Duration
Start date: 2019-05-01, End date: 2024-04-30
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 ETASECS
Project Extremely Thin Absorbers for Solar Energy Conversion and Storage
Researcher (PI) Avner Rothschild
Host Institution (HI) TECHNION - ISRAEL INSTITUTE OF TECHNOLOGY
Call Details Consolidator Grant (CoG), PE8, ERC-2013-CoG
Summary ETASECS aims at making a breakthrough in the development of photoelectrochemical (PEC) cells for solar-powered water splitting that can be readily integrated with PV cells to provide storage capacity in the form of hydrogen. It builds upon our recent invention for resonant light trapping in ultrathin films of iron oxide (a-Fe2O3), which enables overcoming the deleterious trade-off between light absorption and charge carrier collection efficiency. Although we recently broke the water photo-oxidation record by any a-Fe2O3 photoanode reported to date, the losses are still high and there is plenty of room for further improvements that will lead to a remakable enhancement in the performance of our photoanodes, reaching quantum efficiency level similar to state-of-the-art PV cells. ETASECS aims at reaching this ambitious goal, which is essential for demonstrating the competitiveness of PEC+PV tandem systems for solar energy conversion and storage. Towards this end WP1 will combine theory, modelling and simulations, state-of-the-art experimental methods and advanced diagnostic techniques in order to identify and quantify the different losses in our devices. This work will guide the optimization work in WP2 that will suppress the losses at the photoanode and insure optimal electrical and optical coupling of the PEC and PV cells. We will also explore advanced photon management schemes that will go beyond our current light trapping scheme by combining synergic optical and nanophotonics effects. WP3 will integrate the PEC and PV cells and test their properties and performance. WP4 will disseminate our progress and achievements in professional and public forums. The innovations that will emerge from this frontier research will be further pursued in proof of concept follow up investigations that will demonstrate the feasibility of this technology. Success along these lines holds exciting promises for ground breaking progress towards large scale deployment of solar energy.
Summary
ETASECS aims at making a breakthrough in the development of photoelectrochemical (PEC) cells for solar-powered water splitting that can be readily integrated with PV cells to provide storage capacity in the form of hydrogen. It builds upon our recent invention for resonant light trapping in ultrathin films of iron oxide (a-Fe2O3), which enables overcoming the deleterious trade-off between light absorption and charge carrier collection efficiency. Although we recently broke the water photo-oxidation record by any a-Fe2O3 photoanode reported to date, the losses are still high and there is plenty of room for further improvements that will lead to a remakable enhancement in the performance of our photoanodes, reaching quantum efficiency level similar to state-of-the-art PV cells. ETASECS aims at reaching this ambitious goal, which is essential for demonstrating the competitiveness of PEC+PV tandem systems for solar energy conversion and storage. Towards this end WP1 will combine theory, modelling and simulations, state-of-the-art experimental methods and advanced diagnostic techniques in order to identify and quantify the different losses in our devices. This work will guide the optimization work in WP2 that will suppress the losses at the photoanode and insure optimal electrical and optical coupling of the PEC and PV cells. We will also explore advanced photon management schemes that will go beyond our current light trapping scheme by combining synergic optical and nanophotonics effects. WP3 will integrate the PEC and PV cells and test their properties and performance. WP4 will disseminate our progress and achievements in professional and public forums. The innovations that will emerge from this frontier research will be further pursued in proof of concept follow up investigations that will demonstrate the feasibility of this technology. Success along these lines holds exciting promises for ground breaking progress towards large scale deployment of solar energy.
Max ERC Funding
2 150 000 €
Duration
Start date: 2014-09-01, End date: 2019-08-31
Project acronym FACT
Project Factorizing the wave function of large quantum systems
Researcher (PI) Eberhard Gross
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Advanced Grant (AdG), PE3, ERC-2017-ADG
Summary This proposal puts forth a novel strategy to tackle large quantum systems. A variety of highly sophisticated methods such as quantum Monte Carlo, configuration interaction, coupled cluster, tensor networks, Feynman diagrams, dynamical mean-field theory, density functional theory, and semi-classical techniques have been developed to deal with the enormous complexity of the many-particle Schrödinger equation. The goal of our proposal is not to add another method to these standard techniques but, instead, we develop a systematic way of combining them. The essential ingredient is a novel way of decomposing the wave function without approximation into factors that describe subsystems of the full quantum system. This so-called exact factorization is asymmetric. In the case of two subsystems, one factor is a wave function satisfying a regular Schrödinger equation, while the other factor is a conditional probability amplitude satisfying a more complicated Schrödinger-like equation with a non-local, non-linear and non-Hermitian “Hamiltonian”. Since each subsystem is necessarily smaller than the full system, the above standard techniques can be applied more efficiently and, most importantly, different standard techniques can be applied to different subsystems. The power of the exact factorization lies in its versatility. Here we apply the technique to five different scenarios: The first two deal with non-adiabatic effects in (i) molecules and (ii) solids. Here the natural subsystems are electrons and nuclei. The third scenario deals with nuclear motion in (iii) molecules attached to semi-infinite metallic leads, requiring three subsystems: the electrons, the nuclei in the leads which ultimately reduce to a phonon bath, and the molecular nuclei which may perform large-amplitude movements, such as current-induced isomerization, (iv) purely electronic correlations, and (v) the interaction of matter with the quantized electromagnetic field, i.e., electrons, nuclei and photons.
Summary
This proposal puts forth a novel strategy to tackle large quantum systems. A variety of highly sophisticated methods such as quantum Monte Carlo, configuration interaction, coupled cluster, tensor networks, Feynman diagrams, dynamical mean-field theory, density functional theory, and semi-classical techniques have been developed to deal with the enormous complexity of the many-particle Schrödinger equation. The goal of our proposal is not to add another method to these standard techniques but, instead, we develop a systematic way of combining them. The essential ingredient is a novel way of decomposing the wave function without approximation into factors that describe subsystems of the full quantum system. This so-called exact factorization is asymmetric. In the case of two subsystems, one factor is a wave function satisfying a regular Schrödinger equation, while the other factor is a conditional probability amplitude satisfying a more complicated Schrödinger-like equation with a non-local, non-linear and non-Hermitian “Hamiltonian”. Since each subsystem is necessarily smaller than the full system, the above standard techniques can be applied more efficiently and, most importantly, different standard techniques can be applied to different subsystems. The power of the exact factorization lies in its versatility. Here we apply the technique to five different scenarios: The first two deal with non-adiabatic effects in (i) molecules and (ii) solids. Here the natural subsystems are electrons and nuclei. The third scenario deals with nuclear motion in (iii) molecules attached to semi-infinite metallic leads, requiring three subsystems: the electrons, the nuclei in the leads which ultimately reduce to a phonon bath, and the molecular nuclei which may perform large-amplitude movements, such as current-induced isomerization, (iv) purely electronic correlations, and (v) the interaction of matter with the quantized electromagnetic field, i.e., electrons, nuclei and photons.
Max ERC Funding
2 443 932 €
Duration
Start date: 2019-09-01, End date: 2024-08-31
Project acronym FIELDGRADIENTS
Project Phase Transitions and Chemical Reactions in Electric Field Gradients
Researcher (PI) Yoav Tsori
Host Institution (HI) BEN-GURION UNIVERSITY OF THE NEGEV
Call Details Starting Grant (StG), PE3, ERC-2010-StG_20091028
Summary We will study phase transitions and chemical and biological reactions in liquid mixtures
in electric field gradients. These new phase transitions are essential in statistical
physics and thermodynamics. We will examine theoretically the complex and yet unexplored
phase ordering dynamics in which droplets nucleate and move under the external nonuniform
force. We will look in detail at the interfacial instabilities which develop when the
field is increased. We will investigate how time-varying potentials produce
electromagnetic waves and how their spatial decay in the bistable liquid leads to phase
changes.
These transitions open a new and general way to control the spatio-temporal behaviour of
chemical reactions by directly manipulating the solvents' concentrations. When two or more
reagents are preferentially soluble in one of the mixture's components, field-induced
phase separation leads to acceleration of the reaction. When the reagents are soluble in
different solvents, field-induced demixing will lead to the reaction taking place at a
slow rate and at a two-dimensional surface. Additionally, the electric field allows us to
turn the reaction on or off. The numerical study and simulations will be complemented by
experiments. We will study theoretically and experimentally biochemical reactions. We will
find how actin-related structures are affected by field gradients. Using an electric field
as a tool we will control the rate of actin polymerisation. We will investigate if an
external field can damage cancer cells by disrupting their actin-related activity. The above
phenomena will be studied in a microfluidics environment. We will elucidate the separation
hydrodynamics occurring when thermodynamically miscible liquids flow in a channel and how
electric fields can reversibly create and destroy optical interfaces, as is relevant in
optofluidics. Chemical and biological reactions will be examined in the context of
lab-on-a-chip.
Summary
We will study phase transitions and chemical and biological reactions in liquid mixtures
in electric field gradients. These new phase transitions are essential in statistical
physics and thermodynamics. We will examine theoretically the complex and yet unexplored
phase ordering dynamics in which droplets nucleate and move under the external nonuniform
force. We will look in detail at the interfacial instabilities which develop when the
field is increased. We will investigate how time-varying potentials produce
electromagnetic waves and how their spatial decay in the bistable liquid leads to phase
changes.
These transitions open a new and general way to control the spatio-temporal behaviour of
chemical reactions by directly manipulating the solvents' concentrations. When two or more
reagents are preferentially soluble in one of the mixture's components, field-induced
phase separation leads to acceleration of the reaction. When the reagents are soluble in
different solvents, field-induced demixing will lead to the reaction taking place at a
slow rate and at a two-dimensional surface. Additionally, the electric field allows us to
turn the reaction on or off. The numerical study and simulations will be complemented by
experiments. We will study theoretically and experimentally biochemical reactions. We will
find how actin-related structures are affected by field gradients. Using an electric field
as a tool we will control the rate of actin polymerisation. We will investigate if an
external field can damage cancer cells by disrupting their actin-related activity. The above
phenomena will be studied in a microfluidics environment. We will elucidate the separation
hydrodynamics occurring when thermodynamically miscible liquids flow in a channel and how
electric fields can reversibly create and destroy optical interfaces, as is relevant in
optofluidics. Chemical and biological reactions will be examined in the context of
lab-on-a-chip.
Max ERC Funding
1 482 200 €
Duration
Start date: 2010-08-01, End date: 2015-07-31
Project acronym FQHE
Project Statistics of Fractionally Charged Quasi-Particles
Researcher (PI) Mordehai (Moty) Heiblum
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Advanced Grant (AdG), PE3, ERC-2008-AdG
Summary The discovery of the fractional quantum Hall effect created a revolution in solid state research by introducing a new state of matter resulting from strong electron interactions. The new state is characterized by excitations (quasi-particles) that carry fractional charge, which are expected to obey fractional statistics. While odd denominator fractional states are expected to have an abelian statistics, the newly discovered 5/2 even denominator fractional state is expected to have a non-abelian statistics. Moreover, a large number of emerging proposals predict that the latter state can be employed for topological quantum computing ( Station Q was founded by Microsoft Corp. in order to pursue this goal). This proposal aims at studying the abelian and non-abelian fractional charges, and in particular to observe their peculiar statistics. While charges are preferably determined by measuring quantum shot noise, their statistics must be determined via interference experiments, where one particle goes around another. The experiments are very demanding since the even denominator fractions turn to be very fragile and thus can be observed only in the purest possible two dimensional electron gas and at the lowest temperatures. While until very recently such high quality samples were available only by a single grower (in the USA), we have the capability now to grow extremely pure samples with profound even denominator states. As will be detailed in the proposal, we have all the necessary tools to study charge and statistics of these fascinating excitations, due to our experience in crystal growth, shot noise and interferometry measurements.
Summary
The discovery of the fractional quantum Hall effect created a revolution in solid state research by introducing a new state of matter resulting from strong electron interactions. The new state is characterized by excitations (quasi-particles) that carry fractional charge, which are expected to obey fractional statistics. While odd denominator fractional states are expected to have an abelian statistics, the newly discovered 5/2 even denominator fractional state is expected to have a non-abelian statistics. Moreover, a large number of emerging proposals predict that the latter state can be employed for topological quantum computing ( Station Q was founded by Microsoft Corp. in order to pursue this goal). This proposal aims at studying the abelian and non-abelian fractional charges, and in particular to observe their peculiar statistics. While charges are preferably determined by measuring quantum shot noise, their statistics must be determined via interference experiments, where one particle goes around another. The experiments are very demanding since the even denominator fractions turn to be very fragile and thus can be observed only in the purest possible two dimensional electron gas and at the lowest temperatures. While until very recently such high quality samples were available only by a single grower (in the USA), we have the capability now to grow extremely pure samples with profound even denominator states. As will be detailed in the proposal, we have all the necessary tools to study charge and statistics of these fascinating excitations, due to our experience in crystal growth, shot noise and interferometry measurements.
Max ERC Funding
2 000 000 €
Duration
Start date: 2009-01-01, End date: 2013-12-31
Project acronym FRACTFRICT
Project Fracture and Friction: Rapid Dynamics of Material Failure
Researcher (PI) Jay Fineberg
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Advanced Grant (AdG), PE3, ERC-2010-AdG_20100224
Summary FractFrict is a comprehensive study of the space-time dynamics that lead to the failure of both bulk materials and frictionally bound interfaces. In these systems, failure is precipitated by rapidly moving singular fields at the tips of propagating cracks or crack-like fronts that cause material damage at microscopic scales. These generate damage that is macroscopically reflected as characteristic large-scale, modes of material failure. Thus, the structure of the fields that microscopically drive failure is critically important for an overall understanding of how macroscopic failure occurs.
The innovative real-time measurements proposed here will provide fundamental understanding of the form of the singular fields, their modes of regularization and their relation to the resultant macroscopic modes of failure. Encompassing different classes of bulk materials and material interfaces.
We aim to:
[1] To establish a fundamental understanding of the dynamics of the near-tip singular fields, their regularization modes and how they couple to the macroscopic dynamics in both frictional motion and fracture.
[2] To determine the types of singular failure processes in different classes of materials and interfaces (e.g. the brittle to ductile transition in amorphous materials, the role of fast fracture processes in frictional motion).
[3] To establish local (microscopic) laws of friction/failure and how they evolve into their macroscopic counterparts
[4]. To identify the existence and origins of crack instabilities in bulk and interface failure
The insights obtained in this research will enable us to manipulate and/or predict material failure modes. The results of this study will shed considerable new light on fundamental open questions in fields as diverse as material design, tribology and geophysics.
Summary
FractFrict is a comprehensive study of the space-time dynamics that lead to the failure of both bulk materials and frictionally bound interfaces. In these systems, failure is precipitated by rapidly moving singular fields at the tips of propagating cracks or crack-like fronts that cause material damage at microscopic scales. These generate damage that is macroscopically reflected as characteristic large-scale, modes of material failure. Thus, the structure of the fields that microscopically drive failure is critically important for an overall understanding of how macroscopic failure occurs.
The innovative real-time measurements proposed here will provide fundamental understanding of the form of the singular fields, their modes of regularization and their relation to the resultant macroscopic modes of failure. Encompassing different classes of bulk materials and material interfaces.
We aim to:
[1] To establish a fundamental understanding of the dynamics of the near-tip singular fields, their regularization modes and how they couple to the macroscopic dynamics in both frictional motion and fracture.
[2] To determine the types of singular failure processes in different classes of materials and interfaces (e.g. the brittle to ductile transition in amorphous materials, the role of fast fracture processes in frictional motion).
[3] To establish local (microscopic) laws of friction/failure and how they evolve into their macroscopic counterparts
[4]. To identify the existence and origins of crack instabilities in bulk and interface failure
The insights obtained in this research will enable us to manipulate and/or predict material failure modes. The results of this study will shed considerable new light on fundamental open questions in fields as diverse as material design, tribology and geophysics.
Max ERC Funding
2 265 399 €
Duration
Start date: 2010-12-01, End date: 2016-11-30
Project acronym HQMAT
Project New Horizons in Quantum Matter: From Critical Fluids to High Temperature Superconductivity
Researcher (PI) Erez BERG
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Consolidator Grant (CoG), PE3, ERC-2018-COG
Summary Understanding the low-temperature behavior of quantum correlated materials has long been one of the central challenges in condensed matter physics. Such materials exhibit a number of interesting phenomena, such as anomalous transport behavior, complex phase diagrams, and high-temperature superconductivity. However, their understanding has been hindered by the lack of suitable theoretical tools to handle such strongly interacting quantum ``liquids.''
Recent years have witnessed a wave of renewed interest in this long-standing, deep problem, both from condensed matter, high energy, and quantum information physicists. The goal of this research program is to exploit the recent progress on these problems to open new ways of understanding strongly-coupled unconventional quantum fluids. We will perform large-scale, sign problem-free QMC simulations of metals close to quantum critical points, focusing on new regimes beyond the traditional paradigms. New ways to diagnose transport from QMC data will be developed. Exotic phase transitions between an ordinary and a topologically-ordered, fractionalized metal will be studied. In addition, insights will be gained from analytical studies of strongly coupled lattice models, starting from the tractable limit of a large number of degrees of freedom per unit cell. The thermodynamic and transport properties of these models will be studied. These solvable examples will be used to provide a new window into the properties of strongly coupled quantum matter. We will seek ``organizing principles'' to describe such matter, such as emergent local quantum critical behavior and a hydrodynamic description of electron flow. Connections will be made with the ideas of universal bounds on transport and on the rate of spread of quantum information, as well as with insights from other techniques. While our study will mostly focus on generic, universal features of quantum fluids, implications for specific materials will also be studied.
Summary
Understanding the low-temperature behavior of quantum correlated materials has long been one of the central challenges in condensed matter physics. Such materials exhibit a number of interesting phenomena, such as anomalous transport behavior, complex phase diagrams, and high-temperature superconductivity. However, their understanding has been hindered by the lack of suitable theoretical tools to handle such strongly interacting quantum ``liquids.''
Recent years have witnessed a wave of renewed interest in this long-standing, deep problem, both from condensed matter, high energy, and quantum information physicists. The goal of this research program is to exploit the recent progress on these problems to open new ways of understanding strongly-coupled unconventional quantum fluids. We will perform large-scale, sign problem-free QMC simulations of metals close to quantum critical points, focusing on new regimes beyond the traditional paradigms. New ways to diagnose transport from QMC data will be developed. Exotic phase transitions between an ordinary and a topologically-ordered, fractionalized metal will be studied. In addition, insights will be gained from analytical studies of strongly coupled lattice models, starting from the tractable limit of a large number of degrees of freedom per unit cell. The thermodynamic and transport properties of these models will be studied. These solvable examples will be used to provide a new window into the properties of strongly coupled quantum matter. We will seek ``organizing principles'' to describe such matter, such as emergent local quantum critical behavior and a hydrodynamic description of electron flow. Connections will be made with the ideas of universal bounds on transport and on the rate of spread of quantum information, as well as with insights from other techniques. While our study will mostly focus on generic, universal features of quantum fluids, implications for specific materials will also be studied.
Max ERC Funding
1 515 400 €
Duration
Start date: 2019-01-01, End date: 2023-12-31
Project acronym HydraMechanics
Project Mechanical Aspects of Hydra Morphogenesis
Researcher (PI) Kinneret Magda KEREN
Host Institution (HI) TECHNION - ISRAEL INSTITUTE OF TECHNOLOGY
Call Details Consolidator Grant (CoG), PE3, ERC-2018-COG
Summary Morphogenesis is one of the most remarkable examples of biological pattern formation. Despite substantial progress in the field, we still do not understand the organizational principles responsible for the robust convergence of the morphogenesis process, across scales, to form viable organisms under variable conditions. We focus here on the less-studied mechanical aspects of this problem, and aim to uncover how mechanical forces and feedback contribute to the formation and stabilization of the body plan. Regenerating Hydra offer a powerful platform to explore this direction, thanks to their simple body plan, extraordinary regeneration capabilities, and the accessibility and flexibility of their tissues. We propose to follow the regeneration of excised tissue segments, which inherit an aligned supra-cellular cytoskeletal organization from the parent Hydra, as well as cell aggregates, which lack any prior organization. We will employ advanced microscopy techniques and develop elaborate image analysis tools to track cytoskeletal organization and collective cell migration and correlate them with global tissue morphology, from the onset of regeneration all the way to the formation of complete animals. Furthermore, to directly probe the influence of mechanics on Hydra morphogenesis, we propose to apply various mechanical perturbations, and intervene with the axis formation process using external forces and mechanical constraints. Overall, the proposed work seeks to develop an effective phenomenological description of morphogenesis during Hydra regeneration, at the level of cells and tissues, and reveal the mechanical basis of this process. More generally, our research will shed light on the role of mechanics in animal morphogenesis, and inspire new approaches for using external forces to direct tissue engineering and advance regenerative medicine.
Summary
Morphogenesis is one of the most remarkable examples of biological pattern formation. Despite substantial progress in the field, we still do not understand the organizational principles responsible for the robust convergence of the morphogenesis process, across scales, to form viable organisms under variable conditions. We focus here on the less-studied mechanical aspects of this problem, and aim to uncover how mechanical forces and feedback contribute to the formation and stabilization of the body plan. Regenerating Hydra offer a powerful platform to explore this direction, thanks to their simple body plan, extraordinary regeneration capabilities, and the accessibility and flexibility of their tissues. We propose to follow the regeneration of excised tissue segments, which inherit an aligned supra-cellular cytoskeletal organization from the parent Hydra, as well as cell aggregates, which lack any prior organization. We will employ advanced microscopy techniques and develop elaborate image analysis tools to track cytoskeletal organization and collective cell migration and correlate them with global tissue morphology, from the onset of regeneration all the way to the formation of complete animals. Furthermore, to directly probe the influence of mechanics on Hydra morphogenesis, we propose to apply various mechanical perturbations, and intervene with the axis formation process using external forces and mechanical constraints. Overall, the proposed work seeks to develop an effective phenomenological description of morphogenesis during Hydra regeneration, at the level of cells and tissues, and reveal the mechanical basis of this process. More generally, our research will shed light on the role of mechanics in animal morphogenesis, and inspire new approaches for using external forces to direct tissue engineering and advance regenerative medicine.
Max ERC Funding
2 000 000 €
Duration
Start date: 2019-02-01, End date: 2024-01-31
Project acronym LEGOTOP
Project From Local Elements to Globally Ordered TOPological states of matter
Researcher (PI) Yuval OREG
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Advanced Grant (AdG), PE3, ERC-2017-ADG
Summary We present a novel constructive approach for realizations of topological states of matter. Our approach starts with well-understood building blocks, and proceeds towards coupling them to create the desired states. This approach promises both a guide for a tunable experimental realization of states which have not been observed so far, and a theoretical tool for deeper understanding of different topological states, their dualities and inter-relations.
We will apply the constructive approach in two different directions. In the first direction our goal will be the construction of topological superconductors. Our tool will be Josephson junctions in which superconductors are coupled by two- and three-dimensional electronic non-superconducting systems. Two dimensional examples include transition metal dichalcogenides, Quantum Hall states, Quantum Anomalous Hall states, and the (111) bi-layer state, which may be viewed as a fractionalized electron-hole condensate. Three dimensional examples include Weyl semi-metals and weak topological insulators.
In the second direction our goal is the construction of fractionalized spin liquid states. Our building block will be a Majorana-Cooper box, which is a superconducting quantum dot coupled to semi-conducting wires that host Majorana zero modes. We will consider arrays of such boxes. The ratio of the box's charging energy to inter-box tunnel-coupling determines whether the array is superconducting or insulating. We will aim to use insulating arrays for realizing fractionalized and non-abelian spin liquids, study the transition to the superconducting state, and search for possible relations between the topological properties on both sides of the transition.
A deeper comprehension and a feasible path for realization of these states would have a profound effect on the field of topological matter and will open novel avenues for universal topological quantum computers.
Summary
We present a novel constructive approach for realizations of topological states of matter. Our approach starts with well-understood building blocks, and proceeds towards coupling them to create the desired states. This approach promises both a guide for a tunable experimental realization of states which have not been observed so far, and a theoretical tool for deeper understanding of different topological states, their dualities and inter-relations.
We will apply the constructive approach in two different directions. In the first direction our goal will be the construction of topological superconductors. Our tool will be Josephson junctions in which superconductors are coupled by two- and three-dimensional electronic non-superconducting systems. Two dimensional examples include transition metal dichalcogenides, Quantum Hall states, Quantum Anomalous Hall states, and the (111) bi-layer state, which may be viewed as a fractionalized electron-hole condensate. Three dimensional examples include Weyl semi-metals and weak topological insulators.
In the second direction our goal is the construction of fractionalized spin liquid states. Our building block will be a Majorana-Cooper box, which is a superconducting quantum dot coupled to semi-conducting wires that host Majorana zero modes. We will consider arrays of such boxes. The ratio of the box's charging energy to inter-box tunnel-coupling determines whether the array is superconducting or insulating. We will aim to use insulating arrays for realizing fractionalized and non-abelian spin liquids, study the transition to the superconducting state, and search for possible relations between the topological properties on both sides of the transition.
A deeper comprehension and a feasible path for realization of these states would have a profound effect on the field of topological matter and will open novel avenues for universal topological quantum computers.
Max ERC Funding
1 532 163 €
Duration
Start date: 2018-10-01, End date: 2023-09-30
