Project acronym ARENA
Project Arrays of entangled atoms
Researcher (PI) Antoine Browaeys
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Country France
Call Details Starting Grant (StG), PE2, ERC-2009-StG
Summary The goal of this project is to prepare in a deterministic way, and then to characterize, various entangled states of up to 25 individual atoms held in an array of optical tweezers. Such a system provides a new arena to explore quantum entangled states of a large number of particles. Entanglement is the existence of quantum correlations between different parts of a system, and it is recognized as an essential property that distinguishes the quantum and the classical worlds. It is also a resource in various areas of physics, such as quantum information processing, quantum metrology, correlated quantum systems and quantum simulation. In the proposed design, each site is individually addressable, which enables single atom manipulation and detection. This will provide the largest entangled state ever produced and fully characterized at the individual particle level. The experiment will be implemented by combining two crucial novel features, that I was able to demonstrate very recently: first, the manipulation of quantum bits written on long-lived hyperfine ground states of single ultra-cold atoms trapped in microscopic optical tweezers; second, the generation of entanglement by using the strong long-range interactions between Rydberg states. These interactions lead to the so-called dipole blockade , and enable the preparation of various classes of entangled states, such as states carrying only one excitation (W states), and states analogous to Schrödinger s cats (GHZ states). Finally, I will also explore strategies to protect these states against decoherence, developed in the framework of fault-tolerant and topological quantum computing. This project therefore combines an experimental challenge and the exploration of entanglement in a mesoscopic system.
Summary
The goal of this project is to prepare in a deterministic way, and then to characterize, various entangled states of up to 25 individual atoms held in an array of optical tweezers. Such a system provides a new arena to explore quantum entangled states of a large number of particles. Entanglement is the existence of quantum correlations between different parts of a system, and it is recognized as an essential property that distinguishes the quantum and the classical worlds. It is also a resource in various areas of physics, such as quantum information processing, quantum metrology, correlated quantum systems and quantum simulation. In the proposed design, each site is individually addressable, which enables single atom manipulation and detection. This will provide the largest entangled state ever produced and fully characterized at the individual particle level. The experiment will be implemented by combining two crucial novel features, that I was able to demonstrate very recently: first, the manipulation of quantum bits written on long-lived hyperfine ground states of single ultra-cold atoms trapped in microscopic optical tweezers; second, the generation of entanglement by using the strong long-range interactions between Rydberg states. These interactions lead to the so-called dipole blockade , and enable the preparation of various classes of entangled states, such as states carrying only one excitation (W states), and states analogous to Schrödinger s cats (GHZ states). Finally, I will also explore strategies to protect these states against decoherence, developed in the framework of fault-tolerant and topological quantum computing. This project therefore combines an experimental challenge and the exploration of entanglement in a mesoscopic system.
Max ERC Funding
1 449 600 €
Duration
Start date: 2009-12-01, End date: 2014-11-30
Project acronym ARIADNE
Project ARgon ImAging DetectioN chambEr
Researcher (PI) Konstantinos Mavrokoridis
Host Institution (HI) THE UNIVERSITY OF LIVERPOOL
Country United Kingdom
Call Details Starting Grant (StG), PE2, ERC-2015-STG
Summary This proposal outlines a plan to combine Charge Couple Device (CCD) camera technologies with two-phase Liquid Argon Time Projection Chambers (LAr TPCs) utilising THick Gas Electron Multipliers (THGEMs) to evolve a next generation neutrino detector. This will be an entirely new readout option, and will open the prospect of revolutionary discoveries in fundamental particle physics. Furthermore, the Compton imaging power of this technology will be developed, which will have diverse applications in novel medical imaging techniques and detection of concealed nuclear materials.
Colossal LAr TPCs are the future for long-baseline-neutrino-oscillation physics around which the international neutrino community is rallying, with the common goal of discovering new physics beyond the Standard Model, which holds the key to our understanding of phenomena such as dark matter and the matter-antimatter asymmetry.
I have successfully provided a first demonstration of photographic capturing of muon tracks and single gammas interacting in the Liverpool 40 l LAr TPC using a CCD camera and THGEM. I propose an ambitious project of extensive research to mature this innovative LAr optical readout technology. I will construct a 650 l LAr TPC with integrated CCD/THGEM readout, capable of containing sufficient tracking information for full development and characterisation of this novel detector, with the goal of realising this game-changing technology in the planned future giant LAr TPCs. Camera readout can replace the current charge readout technology and associated scalability complications, and the excellent energy thresholds will enhance detector performance as well as extend research avenues to lower energy fundamental physics.
Also, I will explore the Compton imaging capability of LAr CCD/THGEM technology; the superiority of the energy threshold and spatial resolution of this system can offer significant advancement to medical imaging and the detection of concealed nuclear materials.
Summary
This proposal outlines a plan to combine Charge Couple Device (CCD) camera technologies with two-phase Liquid Argon Time Projection Chambers (LAr TPCs) utilising THick Gas Electron Multipliers (THGEMs) to evolve a next generation neutrino detector. This will be an entirely new readout option, and will open the prospect of revolutionary discoveries in fundamental particle physics. Furthermore, the Compton imaging power of this technology will be developed, which will have diverse applications in novel medical imaging techniques and detection of concealed nuclear materials.
Colossal LAr TPCs are the future for long-baseline-neutrino-oscillation physics around which the international neutrino community is rallying, with the common goal of discovering new physics beyond the Standard Model, which holds the key to our understanding of phenomena such as dark matter and the matter-antimatter asymmetry.
I have successfully provided a first demonstration of photographic capturing of muon tracks and single gammas interacting in the Liverpool 40 l LAr TPC using a CCD camera and THGEM. I propose an ambitious project of extensive research to mature this innovative LAr optical readout technology. I will construct a 650 l LAr TPC with integrated CCD/THGEM readout, capable of containing sufficient tracking information for full development and characterisation of this novel detector, with the goal of realising this game-changing technology in the planned future giant LAr TPCs. Camera readout can replace the current charge readout technology and associated scalability complications, and the excellent energy thresholds will enhance detector performance as well as extend research avenues to lower energy fundamental physics.
Also, I will explore the Compton imaging capability of LAr CCD/THGEM technology; the superiority of the energy threshold and spatial resolution of this system can offer significant advancement to medical imaging and the detection of concealed nuclear materials.
Max ERC Funding
1 837 911 €
Duration
Start date: 2016-03-01, End date: 2021-08-31
Project acronym ARQADIA
Project Artificial quantum materials with photons: many-body physics and topology
Researcher (PI) Sylvain Ravets
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Country France
Call Details Starting Grant (StG), PE2, ERC-2020-STG
Summary Physical systems featuring strong electronic correlations exhibit fascinating phenomena, as exemplified by high-Tc superconductivity, quantum magnetism or fractional quantum Hall physics. Inspired by these effects, new ideas have emerged to harness strongly correlated phases in artificial quantum materials, and use them as a resource for fundamental science and for quantum technology. Promising approaches for producing quantum devices are found in condensed matter platforms: one can indeed benefit from nanofabrication to engineer systems that are compact, versatile, and which can potentially be integrated in large-scale architectures. The main goal of ARQADIA is to engineer and study quantum correlated and topological phases of light using artificial photonic materials that I will fabricate in a solid-state platform. I will use exciton-polaritons in semiconductor microcavities, which are hybrid quasiparticles resulting from strong coupling between cavity photons and quantum well excitons. Polaritons are particularly attractive since they combine the best of two worlds: (i) through their photon component, they can be confined in microstrucutres and manipulated using optical spectroscopy; (ii) through their matter component, interactions between polaritons can be tuned and reinforced. Moreover, polaritons can be detected through the decay of cavity photons, which means that they naturally implement out-of-equilibrium physics and allow addressing fascinating questions related to the interplay between quantum correlations and dissipation. Within ARQADIA, I will tackle the challenge of engineering quantum correlations between polaritons via a technological breakthrough: I will insert active materials featuring strongly interacting excitons in microcavity lattices. I will use these materials to study out-of-equilibrium strongly correlated phases in vastly different regimes: from 1D to 2D, from weakly to strongly interacting and from topologically trivial to non-trivial.
Summary
Physical systems featuring strong electronic correlations exhibit fascinating phenomena, as exemplified by high-Tc superconductivity, quantum magnetism or fractional quantum Hall physics. Inspired by these effects, new ideas have emerged to harness strongly correlated phases in artificial quantum materials, and use them as a resource for fundamental science and for quantum technology. Promising approaches for producing quantum devices are found in condensed matter platforms: one can indeed benefit from nanofabrication to engineer systems that are compact, versatile, and which can potentially be integrated in large-scale architectures. The main goal of ARQADIA is to engineer and study quantum correlated and topological phases of light using artificial photonic materials that I will fabricate in a solid-state platform. I will use exciton-polaritons in semiconductor microcavities, which are hybrid quasiparticles resulting from strong coupling between cavity photons and quantum well excitons. Polaritons are particularly attractive since they combine the best of two worlds: (i) through their photon component, they can be confined in microstrucutres and manipulated using optical spectroscopy; (ii) through their matter component, interactions between polaritons can be tuned and reinforced. Moreover, polaritons can be detected through the decay of cavity photons, which means that they naturally implement out-of-equilibrium physics and allow addressing fascinating questions related to the interplay between quantum correlations and dissipation. Within ARQADIA, I will tackle the challenge of engineering quantum correlations between polaritons via a technological breakthrough: I will insert active materials featuring strongly interacting excitons in microcavity lattices. I will use these materials to study out-of-equilibrium strongly correlated phases in vastly different regimes: from 1D to 2D, from weakly to strongly interacting and from topologically trivial to non-trivial.
Max ERC Funding
1 499 603 €
Duration
Start date: 2021-01-01, End date: 2025-12-31
Project acronym ASTEX
Project Attosecond Science by Transmission and Emission of X-rays
Researcher (PI) Jonathan Philip Marangos
Host Institution (HI) IMPERIAL COLLEGE OF SCIENCE TECHNOLOGY AND MEDICINE
Country United Kingdom
Call Details Advanced Grant (AdG), PE2, ERC-2011-ADG_20110209
Summary "This is a programme of advanced research with potential for high scientific impact and applications to areas of great strategic importance such as renewable energy and biomolecular technology. The aim is to develop and apply a combination of cutting-edge tools to observe and understand dynamics in molecules and condensed phase matter with attosecond temporal and nanometre spatial resolutions. The programme, will exploit two new types of measurements that my group have already begun to develop: high harmonic generation (HHG) spectroscopy and attosecond absorption pump-probe spectroscopy, and will apply them to the measurement of attosecond electron dynamics in large molecules and the condensed phase. These methods rely upon the emission and transmission of soft X-ray attosecond fields that make accessible measurement not only of larger molecules in the gas phase but also thin (micron to nanometre) samples in the condensed phase. This is a research project that will open new frontiers both experimentally and theoretically. The challenge of this research is high and will be met by a concerted programme that is well matched to my teams experimental and theoretical expertise in attosecond physics, ultrafast intense-field science, soft X-ray techniques and advanced techniques for creating gaseous and condensed phase samples."
Summary
"This is a programme of advanced research with potential for high scientific impact and applications to areas of great strategic importance such as renewable energy and biomolecular technology. The aim is to develop and apply a combination of cutting-edge tools to observe and understand dynamics in molecules and condensed phase matter with attosecond temporal and nanometre spatial resolutions. The programme, will exploit two new types of measurements that my group have already begun to develop: high harmonic generation (HHG) spectroscopy and attosecond absorption pump-probe spectroscopy, and will apply them to the measurement of attosecond electron dynamics in large molecules and the condensed phase. These methods rely upon the emission and transmission of soft X-ray attosecond fields that make accessible measurement not only of larger molecules in the gas phase but also thin (micron to nanometre) samples in the condensed phase. This is a research project that will open new frontiers both experimentally and theoretically. The challenge of this research is high and will be met by a concerted programme that is well matched to my teams experimental and theoretical expertise in attosecond physics, ultrafast intense-field science, soft X-ray techniques and advanced techniques for creating gaseous and condensed phase samples."
Max ERC Funding
2 344 390 €
Duration
Start date: 2012-04-01, End date: 2017-03-31
Project acronym ASTRUm
Project Astrophysics with Stored Highy Charged Radionuclides
Researcher (PI) Yury Litvinov
Host Institution (HI) GSI HELMHOLTZZENTRUM FUER SCHWERIONENFORSCHUNG GMBH
Country Germany
Call Details Consolidator Grant (CoG), PE2, ERC-2015-CoG
Summary The main goal of ASTRUm is to employ stored and cooled radioactive ions for forefront nuclear astrophysics research. Four key experiments are proposed to be conducted at GSI in Darmstadt, which holds the only facility to date capable of storing highly charged radionuclides in the required element and energy range. The proposed experiments can hardly be conducted by any other technique or method.
The weak decay matrix element for the transition between the 2.3 keV state in 205Pb and the ground state of 205Tl will be measured via the bound state beta decay measurement of fully ionized 205Tl81+. This will provide the required data to determine the solar pp-neutrino flux integrated over the last 5 million years and will allow us to unveil the astrophysical conditions prior to the formation of the solar system.
The measurements of the alpha-decay width of the 4.033 MeV excited state in 19Ne will allow us to constrain the conditions for the ignition of the rp-process in X-ray bursters.
ASTRUm will open a new field by enabling for the first time measurements of proton- and alpha-capture reaction cross-sections on radioactive nuclei of interest for the p-process of nucleosynthesis.
Last but not least, broad band mass and half-life measurements in a ring is the only technique to precisely determine these key nuclear properties for nuclei with half-lives as short as a millisecond and production rates of below one ion per day.
To accomplish these measurements with highest efficiency, sensitivity and precision, improved detector systems will be developed within ASTRUm. Possible applications of these systems go beyond ASTRUm objectives and will be used in particular in accelerator physics.
The instrumentation and experience gained within ASTRUm will be indispensable for planning the future, next generation storage ring projects, which are launched or proposed at several radioactive ion beam facilities.
Summary
The main goal of ASTRUm is to employ stored and cooled radioactive ions for forefront nuclear astrophysics research. Four key experiments are proposed to be conducted at GSI in Darmstadt, which holds the only facility to date capable of storing highly charged radionuclides in the required element and energy range. The proposed experiments can hardly be conducted by any other technique or method.
The weak decay matrix element for the transition between the 2.3 keV state in 205Pb and the ground state of 205Tl will be measured via the bound state beta decay measurement of fully ionized 205Tl81+. This will provide the required data to determine the solar pp-neutrino flux integrated over the last 5 million years and will allow us to unveil the astrophysical conditions prior to the formation of the solar system.
The measurements of the alpha-decay width of the 4.033 MeV excited state in 19Ne will allow us to constrain the conditions for the ignition of the rp-process in X-ray bursters.
ASTRUm will open a new field by enabling for the first time measurements of proton- and alpha-capture reaction cross-sections on radioactive nuclei of interest for the p-process of nucleosynthesis.
Last but not least, broad band mass and half-life measurements in a ring is the only technique to precisely determine these key nuclear properties for nuclei with half-lives as short as a millisecond and production rates of below one ion per day.
To accomplish these measurements with highest efficiency, sensitivity and precision, improved detector systems will be developed within ASTRUm. Possible applications of these systems go beyond ASTRUm objectives and will be used in particular in accelerator physics.
The instrumentation and experience gained within ASTRUm will be indispensable for planning the future, next generation storage ring projects, which are launched or proposed at several radioactive ion beam facilities.
Max ERC Funding
1 874 750 €
Duration
Start date: 2016-04-01, End date: 2021-09-30
Project acronym ASYMMETRY
Project Measurement of CP violation in the B_s system at LHCb
Researcher (PI) Stephanie Hansmann-Menzemer
Host Institution (HI) RUPRECHT-KARLS-UNIVERSITAET HEIDELBERG
Country Germany
Call Details Starting Grant (StG), PE2, ERC-2010-StG_20091028
Summary The Large Hadron collider (LHC) at CERN will be a milestone for the understanding of fundamental interactions and for the future of high energy
physics. Four large experiments at the LHC are complementarily addressing the question of the origin of our Universe by searching for so-called New Physics.
The world of particles and their interactions is nowadays described by the Standard Model. Up to now there is no single measurement from laboratory experiments which contradicts this theory. However, there are still many open questions, thus physicists are convinced that there is a more fundamental theory, which incorporates New Physics.
It is expected that at the LHC either New Physics beyond the Standard Model will be discovered or excluded up to very high energies, which would revolutionize the understanding of particle physics and require completely new experimental and theoretical concepts.
The LHCb (Large Hadron Collider beauty) experiment is dedicated to precision measurements of B hadrons (B hadrons are all particles containing a beauty quark).
The analysis proposed here is the measurement of asymmetries between B_s particles and anti-B_s particles at the LHCb experiment. Any New Physics model will change the rate of observable processes via additional quantum corrections. Particle antiparticle asymmetries are extremely sensitive to these corrections thus a very powerful tool for indirect searches for New Physics contributions. In the past, most of the ground-breaking findings in particle physics, such as the existence of the
charm quark and the existence of a third quark family, have first been observed in indirect searches.
First - still statistically limited - measurements of the asymmetry in the B_s system indicate a 2 sigma deviation from the Standard Model prediction. A precision measurement of this asymmetry is potentially the first observation for New Physics beyond the Standard Model at the LHC. If no hint for New Physics will be found, this measurement will severely restrict the range of potential New Physics models.
Summary
The Large Hadron collider (LHC) at CERN will be a milestone for the understanding of fundamental interactions and for the future of high energy
physics. Four large experiments at the LHC are complementarily addressing the question of the origin of our Universe by searching for so-called New Physics.
The world of particles and their interactions is nowadays described by the Standard Model. Up to now there is no single measurement from laboratory experiments which contradicts this theory. However, there are still many open questions, thus physicists are convinced that there is a more fundamental theory, which incorporates New Physics.
It is expected that at the LHC either New Physics beyond the Standard Model will be discovered or excluded up to very high energies, which would revolutionize the understanding of particle physics and require completely new experimental and theoretical concepts.
The LHCb (Large Hadron Collider beauty) experiment is dedicated to precision measurements of B hadrons (B hadrons are all particles containing a beauty quark).
The analysis proposed here is the measurement of asymmetries between B_s particles and anti-B_s particles at the LHCb experiment. Any New Physics model will change the rate of observable processes via additional quantum corrections. Particle antiparticle asymmetries are extremely sensitive to these corrections thus a very powerful tool for indirect searches for New Physics contributions. In the past, most of the ground-breaking findings in particle physics, such as the existence of the
charm quark and the existence of a third quark family, have first been observed in indirect searches.
First - still statistically limited - measurements of the asymmetry in the B_s system indicate a 2 sigma deviation from the Standard Model prediction. A precision measurement of this asymmetry is potentially the first observation for New Physics beyond the Standard Model at the LHC. If no hint for New Physics will be found, this measurement will severely restrict the range of potential New Physics models.
Max ERC Funding
1 059 240 €
Duration
Start date: 2011-01-01, End date: 2015-12-31
Project acronym AtomicGaugeSimulator
Project Classical and Atomic Quantum Simulation of Gauge Theories in Particle and Condensed Matter Physics
Researcher (PI) Uwe-Jens Richard Christian Wiese
Host Institution (HI) UNIVERSITAET BERN
Country Switzerland
Call Details Advanced Grant (AdG), PE2, ERC-2013-ADG
Summary Gauge theories play a central role in particle and condensed matter physics. Heavy-ion collisions explore the strong dynamics of quarks and gluons, which also governs the deep interior of neutron stars, while strongly correlated electrons determine the physics of high-temperature superconductors and spin liquids. Numerical simulations of such systems are often hindered by sign problems. In quantum link models - an alternative formulation of gauge theories developed by the applicant - gauge fields emerge from discrete quantum variables. In the past year, in close collaboration with atomic physicists, we have established quantum link models as a framework for the atomic quantum simulation of dynamical gauge fields. Abelian gauge theories can be realized with Bose-Fermi mixtures of ultracold atoms in an optical lattice, while non-Abelian gauge fields arise from fermionic constituents embodied by alkaline-earth atoms. Quantum simulators, which do not suffer from the sign problem, shall be constructed to address non-trivial dynamics, including quantum phase transitions in spin liquids, the real-time dynamics of confining strings as well as of chiral symmetry restoration at finite temperature and baryon density, baryon superfluidity, or color-flavor locking. New classical simulation algorithms shall be developed in order to solve severe sign problems, to investigate confining gauge theories, and to validate the proposed quantum simulators. Starting from U(1) and SU(2) gauge theories, an atomic physics tool box shall be developed for quantum simulation of gauge theories of increasing complexity, ultimately aiming at 4-d Quantum Chromodynamics (QCD). This project is based on innovative ideas from particle, condensed matter, and computational physics, and requires an interdisciplinary team of researchers. It has the potential to drastically increase the power of simulations and to address very challenging problems that cannot be solved with classical simulation methods.
Summary
Gauge theories play a central role in particle and condensed matter physics. Heavy-ion collisions explore the strong dynamics of quarks and gluons, which also governs the deep interior of neutron stars, while strongly correlated electrons determine the physics of high-temperature superconductors and spin liquids. Numerical simulations of such systems are often hindered by sign problems. In quantum link models - an alternative formulation of gauge theories developed by the applicant - gauge fields emerge from discrete quantum variables. In the past year, in close collaboration with atomic physicists, we have established quantum link models as a framework for the atomic quantum simulation of dynamical gauge fields. Abelian gauge theories can be realized with Bose-Fermi mixtures of ultracold atoms in an optical lattice, while non-Abelian gauge fields arise from fermionic constituents embodied by alkaline-earth atoms. Quantum simulators, which do not suffer from the sign problem, shall be constructed to address non-trivial dynamics, including quantum phase transitions in spin liquids, the real-time dynamics of confining strings as well as of chiral symmetry restoration at finite temperature and baryon density, baryon superfluidity, or color-flavor locking. New classical simulation algorithms shall be developed in order to solve severe sign problems, to investigate confining gauge theories, and to validate the proposed quantum simulators. Starting from U(1) and SU(2) gauge theories, an atomic physics tool box shall be developed for quantum simulation of gauge theories of increasing complexity, ultimately aiming at 4-d Quantum Chromodynamics (QCD). This project is based on innovative ideas from particle, condensed matter, and computational physics, and requires an interdisciplinary team of researchers. It has the potential to drastically increase the power of simulations and to address very challenging problems that cannot be solved with classical simulation methods.
Max ERC Funding
1 975 242 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
Project acronym ATOMION
Project Exploring hybrid quantum systems of ultracold atoms and ions
Researcher (PI) Michael Karl Koehl
Host Institution (HI) RHEINISCHE FRIEDRICH-WILHELMS-UNIVERSITAT BONN
Country Germany
Call Details Starting Grant (StG), PE2, ERC-2009-StG
Summary We propose to investigate hybrid quantum systems composed of ultracold atoms and ions. The mutual interaction of the cold neutral atoms and the trapped ion offers a wealth of interesting new physical problems. They span from ultracold quantum chemistry over new concepts for quantum information processing to genuine quantum many-body physics. We plan to explore aspects of quantum chemistry with ultracold atoms and ions to obtain a full understanding of the interactions in this hybrid system. We will investigate the regime of low energy collisions and search for Feshbach resonances to tune the interaction strength between atoms and ions. Moreover, we will study collective effects in chemical reactions between a Bose-Einstein condensate and a single ion. Taking advantage of the extraordinary properties of the atom-ion mixture quantum information processing with hybrid systems will be performed. In particular, we plan to realize sympathetic ground state cooling of the ion with a Bose-Einstein condensate. When the ion is immersed into the ultracold neutral atom environment the nature of the decoherence will be tailored by tuning properties of the environment: A dissipative quantum phase transition is predicted when the ion is coupled to a one-dimensional Bose gas. Moreover, we plan to realize a scalable hybrid quantum processor composed of a single ion and an array of neutral atoms in an optical lattice. The third direction we will pursue is related to impurity effects in quantum many-body physics. We plan to study transport through a single impurity or atomic quantum dot with the goal of realizing a single atom transistor. A single atom transistor transfers the quantum state of the impurity coherently to a macroscopic neutral atom current. Finally, we plan to observe Anderson s orthogonality catastrophe in which the presence of a single impurity in a quantum gas orthogonalizes the quantum many-body function of a quantum state with respect to the unperturbed one.
Summary
We propose to investigate hybrid quantum systems composed of ultracold atoms and ions. The mutual interaction of the cold neutral atoms and the trapped ion offers a wealth of interesting new physical problems. They span from ultracold quantum chemistry over new concepts for quantum information processing to genuine quantum many-body physics. We plan to explore aspects of quantum chemistry with ultracold atoms and ions to obtain a full understanding of the interactions in this hybrid system. We will investigate the regime of low energy collisions and search for Feshbach resonances to tune the interaction strength between atoms and ions. Moreover, we will study collective effects in chemical reactions between a Bose-Einstein condensate and a single ion. Taking advantage of the extraordinary properties of the atom-ion mixture quantum information processing with hybrid systems will be performed. In particular, we plan to realize sympathetic ground state cooling of the ion with a Bose-Einstein condensate. When the ion is immersed into the ultracold neutral atom environment the nature of the decoherence will be tailored by tuning properties of the environment: A dissipative quantum phase transition is predicted when the ion is coupled to a one-dimensional Bose gas. Moreover, we plan to realize a scalable hybrid quantum processor composed of a single ion and an array of neutral atoms in an optical lattice. The third direction we will pursue is related to impurity effects in quantum many-body physics. We plan to study transport through a single impurity or atomic quantum dot with the goal of realizing a single atom transistor. A single atom transistor transfers the quantum state of the impurity coherently to a macroscopic neutral atom current. Finally, we plan to observe Anderson s orthogonality catastrophe in which the presence of a single impurity in a quantum gas orthogonalizes the quantum many-body function of a quantum state with respect to the unperturbed one.
Max ERC Funding
1 405 000 €
Duration
Start date: 2009-10-01, End date: 2014-09-30
Project acronym ATOMKI-PPROCESS
Project Nuclear reaction studies relevant to the astrophysical p-process nucleosynthesis
Researcher (PI) Gyoergy Gyuerky
Host Institution (HI) ATOMMAGKUTATO INTEZET
Country Hungary
Call Details Starting Grant (StG), PE2, ERC-2007-StG
Summary The astrophysical p-process, the stellar production mechanism of the heavy, proton rich isotopes (p-isotopes), is one of the least studied processes in nucleosynthesis. The astrophysical site(s) for the p-process could not yet be clearly identified. In order to reproduce the natural abundances of the p-isotopes, the p-process models must take into account a huge nuclear reaction network. A precise knowledge of the rate of the nuclear reactions in this network is essential for a reliable abundance calculation and for a clear assignment of the astrophysical site(s). For lack of experimental data the nuclear physics inputs for the reaction networks are based on statistical model calculations. These calculations are largely untested in the mass and energy range relevant to the p-process and the uncertainties in the reaction rate values result in a correspondingly uncertain prediction of the p-isotope abundances. Therefore, experiments aiming at the determination of reaction rates for the p-process are of great importance. In this project nuclear reaction cross section measurements will be carried out in the mass and energy range of p-process to check the reliability of the statistical model calculations and to put the p-process models on a more reliable base. The accelerators of the Institute of Nuclear Research in Debrecen, Hungary provide the necessary basis for such studies. The p-process model calculations are especially sensitive to the rates of reactions involving alpha particles and heavy nuclei. Because of technical difficulties, so far there are practically no experimental data available on such reactions and the uncertainty in these reaction rates is presently one of the biggest contributions to the uncertainty of p-isotope abundance calculations. With the help of the ERC grant the alpha-induced reaction cross sections can be measured on heavy isotopes for the first time, which could contribute to a better understanding of the astrophysical p-process.
Summary
The astrophysical p-process, the stellar production mechanism of the heavy, proton rich isotopes (p-isotopes), is one of the least studied processes in nucleosynthesis. The astrophysical site(s) for the p-process could not yet be clearly identified. In order to reproduce the natural abundances of the p-isotopes, the p-process models must take into account a huge nuclear reaction network. A precise knowledge of the rate of the nuclear reactions in this network is essential for a reliable abundance calculation and for a clear assignment of the astrophysical site(s). For lack of experimental data the nuclear physics inputs for the reaction networks are based on statistical model calculations. These calculations are largely untested in the mass and energy range relevant to the p-process and the uncertainties in the reaction rate values result in a correspondingly uncertain prediction of the p-isotope abundances. Therefore, experiments aiming at the determination of reaction rates for the p-process are of great importance. In this project nuclear reaction cross section measurements will be carried out in the mass and energy range of p-process to check the reliability of the statistical model calculations and to put the p-process models on a more reliable base. The accelerators of the Institute of Nuclear Research in Debrecen, Hungary provide the necessary basis for such studies. The p-process model calculations are especially sensitive to the rates of reactions involving alpha particles and heavy nuclei. Because of technical difficulties, so far there are practically no experimental data available on such reactions and the uncertainty in these reaction rates is presently one of the biggest contributions to the uncertainty of p-isotope abundance calculations. With the help of the ERC grant the alpha-induced reaction cross sections can be measured on heavy isotopes for the first time, which could contribute to a better understanding of the astrophysical p-process.
Max ERC Funding
750 000 €
Duration
Start date: 2008-07-01, End date: 2013-06-30
Project acronym ATOMPHOTONLOQIP
Project Experimental Linear Optics Quantum Information Processing with Atoms and Photons
Researcher (PI) Jian-Wei Pan
Host Institution (HI) RUPRECHT-KARLS-UNIVERSITAET HEIDELBERG
Country Germany
Call Details Starting Grant (StG), PE2, ERC-2007-StG
Summary Quantum information science and atom optics are among the most active fields in modern physics. In recent years, many theoretical efforts have been made to combine these two fields. Recent experimental progresses have shown the in-principle possibility to perform scalable quantum information processing (QIP) with linear optics and atomic ensembles. The main purpose of the present project is to use atomic qubits as quantum memory and exploit photonic qubits for information transfer and processing to achieve efficient linear optics QIP. On the one hand, utilizing the interaction between laser pulses and atomic ensembles we will experimentally investigate the potentials of atomic ensembles in the gas phase to build quantum repeaters for long-distance quantum communication, that is, to develop a new technological solution for quantum repeaters making use of the effective qubit-type entanglement of two cold atomic ensembles by a projective measurement of individual photons by spontaneous Raman processes. On this basis, we will further investigate the advantages of cold atoms in an optical trap to enhance the coherence time of atomic qubits beyond the threshold for scalable realization of quantum repeaters. Moreover, building on our long experience in research on multi-photon entanglement, we also plan to perform a number of significant experiments in the field of QIP with particular emphasis on fault-tolerant quantum computation, photon-loss-tolerant quantum computation and cluster-state based quantum simulation. Finally, by combining the techniques developed in the above quantum memory and multi-photon interference experiments, we will further experimentally investigate the possibility to achieve quantum teleportation between photonic and atomic qubits, quantum teleportation between remote atomic qubits and efficient entanglement generation via classical feed-forward. The techniques that will be developed in the present project will lay the basis for future large scale
Summary
Quantum information science and atom optics are among the most active fields in modern physics. In recent years, many theoretical efforts have been made to combine these two fields. Recent experimental progresses have shown the in-principle possibility to perform scalable quantum information processing (QIP) with linear optics and atomic ensembles. The main purpose of the present project is to use atomic qubits as quantum memory and exploit photonic qubits for information transfer and processing to achieve efficient linear optics QIP. On the one hand, utilizing the interaction between laser pulses and atomic ensembles we will experimentally investigate the potentials of atomic ensembles in the gas phase to build quantum repeaters for long-distance quantum communication, that is, to develop a new technological solution for quantum repeaters making use of the effective qubit-type entanglement of two cold atomic ensembles by a projective measurement of individual photons by spontaneous Raman processes. On this basis, we will further investigate the advantages of cold atoms in an optical trap to enhance the coherence time of atomic qubits beyond the threshold for scalable realization of quantum repeaters. Moreover, building on our long experience in research on multi-photon entanglement, we also plan to perform a number of significant experiments in the field of QIP with particular emphasis on fault-tolerant quantum computation, photon-loss-tolerant quantum computation and cluster-state based quantum simulation. Finally, by combining the techniques developed in the above quantum memory and multi-photon interference experiments, we will further experimentally investigate the possibility to achieve quantum teleportation between photonic and atomic qubits, quantum teleportation between remote atomic qubits and efficient entanglement generation via classical feed-forward. The techniques that will be developed in the present project will lay the basis for future large scale
Max ERC Funding
1 435 000 €
Duration
Start date: 2008-07-01, End date: 2013-12-31
