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
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 ATTOELECTRONICS
Project Attoelectronics: Steering electrons in atoms and molecules with synthesized waveforms of light
Researcher (PI) Eleftherios Goulielmakis
Host Institution (HI) MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV
Call Details Starting Grant (StG), PE2, ERC-2010-StG_20091028
Summary In order for electronics to meet the ever raising demands for higher speeds of operation, the dimensions of its basic elements drop continuously. This miniaturization, that will soon meet the dimensions of a single molecule or an atom, calls for new approaches in electronics that take advantage, rather than confront the dominant at these scales quantum laws.
Electronics on the scale of atoms and molecules require fields that are able to trigger and to steer electrons at speeds comparable to their intrinsic dynamics, determined by the quantum mechanical laws. For the valence electrons of atoms and molecules, this motion is clocked in tens to thousands of attoseconds, (1 as =10-18 sec) implying the potential for executing basic electronic operations in the PHz regime and beyond. This is approximately ~1000000 times faster as compared to any contemporary technology.
To meet this challenging goal, this project will utilize conceptual and technological advances of attosecond science as its primary tools. First, pulses of light, the fields of which can be sculpted and characterized with attosecond accuracy, for triggering as well as for terminating the ultrafast electron motion in an atom or a molecule. Second, attosecond pulses in the extreme ultraviolet, which can probe and frame-freeze the created electron motion, with unprecedented resolution, and determine the direction and the magnitude of the created currents.
This project will interrogate the limits of the fastest electronic motion that light fields can trigger as well as terminate, a few hundreds of attoseconds later, in an atom or a molecule. In this way it aims to explore new routes of atomic and molecular scale electronic switching at PHz frequencies.
Summary
In order for electronics to meet the ever raising demands for higher speeds of operation, the dimensions of its basic elements drop continuously. This miniaturization, that will soon meet the dimensions of a single molecule or an atom, calls for new approaches in electronics that take advantage, rather than confront the dominant at these scales quantum laws.
Electronics on the scale of atoms and molecules require fields that are able to trigger and to steer electrons at speeds comparable to their intrinsic dynamics, determined by the quantum mechanical laws. For the valence electrons of atoms and molecules, this motion is clocked in tens to thousands of attoseconds, (1 as =10-18 sec) implying the potential for executing basic electronic operations in the PHz regime and beyond. This is approximately ~1000000 times faster as compared to any contemporary technology.
To meet this challenging goal, this project will utilize conceptual and technological advances of attosecond science as its primary tools. First, pulses of light, the fields of which can be sculpted and characterized with attosecond accuracy, for triggering as well as for terminating the ultrafast electron motion in an atom or a molecule. Second, attosecond pulses in the extreme ultraviolet, which can probe and frame-freeze the created electron motion, with unprecedented resolution, and determine the direction and the magnitude of the created currents.
This project will interrogate the limits of the fastest electronic motion that light fields can trigger as well as terminate, a few hundreds of attoseconds later, in an atom or a molecule. In this way it aims to explore new routes of atomic and molecular scale electronic switching at PHz frequencies.
Max ERC Funding
1 262 000 €
Duration
Start date: 2010-12-01, End date: 2016-11-30
Project acronym BinGraSp
Project Modeling the Gravitational Spectrum of Neutron Star Binaries
Researcher (PI) Sebastiano Bernuzzi
Host Institution (HI) FRIEDRICH-SCHILLER-UNIVERSITAT JENA
Call Details Starting Grant (StG), PE2, ERC-2016-STG
Summary The most energetic electromagnetic phenomena in the Universe are believed to be powered by the collision of two neutron stars, the smallest and densest stars on which surface gravity is about 2 billion times stronger than gravity on Earth. However, a definitive identification of neutron star mergers as central engines for short-gamma-ray bursts and kilonovae transients is possible only by direct gravitational-wave observations. The latter provide us with unique information on neutron stars' masses, radii, and spins, including the possibility to set the strongest observational constraints on the unknown equation-of-state of matter at supranuclear densities.
Neutron stars binary mergers are among the main targets for ground-based gravitational-wave interferometers like Advanced LIGO and Virgo, which start operations this year. The astrophysical data analysis of the signals emitted by these sources requires the availability of accurate waveform models, which are missing to date. Hence, the theoretical understanding of the gravitational spectrum is a necessary and urgent step for the development of a gravitational-based astrophysics in the next years.
This project aims at developing, for the first time, a precise theoretical model for the complete gravitational spectrum of neutron star binaries, including the merger and postmerger stages of the coalescence process. Building on the PI's unique expertise and track record, the proposed research exploits synergy between analytical and numerical methods in General Relativity. Results from state of the art nonlinear 3D numerical relativity simulations will be combined with the most advanced analytical framework for the relativistic two-body problem. The model developed here will be used in the first gravitational-wave observations and will dramatically impact multimessenger astrophysics.
Summary
The most energetic electromagnetic phenomena in the Universe are believed to be powered by the collision of two neutron stars, the smallest and densest stars on which surface gravity is about 2 billion times stronger than gravity on Earth. However, a definitive identification of neutron star mergers as central engines for short-gamma-ray bursts and kilonovae transients is possible only by direct gravitational-wave observations. The latter provide us with unique information on neutron stars' masses, radii, and spins, including the possibility to set the strongest observational constraints on the unknown equation-of-state of matter at supranuclear densities.
Neutron stars binary mergers are among the main targets for ground-based gravitational-wave interferometers like Advanced LIGO and Virgo, which start operations this year. The astrophysical data analysis of the signals emitted by these sources requires the availability of accurate waveform models, which are missing to date. Hence, the theoretical understanding of the gravitational spectrum is a necessary and urgent step for the development of a gravitational-based astrophysics in the next years.
This project aims at developing, for the first time, a precise theoretical model for the complete gravitational spectrum of neutron star binaries, including the merger and postmerger stages of the coalescence process. Building on the PI's unique expertise and track record, the proposed research exploits synergy between analytical and numerical methods in General Relativity. Results from state of the art nonlinear 3D numerical relativity simulations will be combined with the most advanced analytical framework for the relativistic two-body problem. The model developed here will be used in the first gravitational-wave observations and will dramatically impact multimessenger astrophysics.
Max ERC Funding
1 432 301 €
Duration
Start date: 2017-10-01, End date: 2022-09-30
Project acronym FDML-RAMAN
Project Stimulated Raman analysis and Raman microscopy with Fourier Domain Mode Locked (FDML) laser sources
Researcher (PI) Robert Alexander Huber
Host Institution (HI) LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN
Call Details Starting Grant (StG), PE2, ERC-2010-StG_20091028
Summary Raman spectroscopy is one of the most specific non-destructive optical techniques to identify the chemical composition of a sample. Further, there is great hope that in the future it may be a powerful biomedical imaging technique for in vitro or in vivo microscopy, providing molecular contrast without exogenous contrast agents.
However, due to the small Raman cross-section, for many applications the acquisition is prohibitively slow. Techniques to solve this problem and to increase the Raman signal levels are coherent anti-Stokes Raman spectroscopy (CARS), surface enhanced Raman spectroscopy (SERS) and stimulated Raman spectroscopy (SRS). However, in many cases, they are currently not able to provide rapid, highly sensitive detection of an undistorted signal with a broad spectral coverage.
The aim of the project is to investigate Fourier domain mode locked (FDML) lasers for the application to stimulated Raman detection. A variety of physical effects, unique to FDML lasers, enables strategies to substantially increase the Raman signal level. This can provide access to highly sensitive Raman spectroscopy and high speed Raman microscopy. The techniques to increase the detection sensitivity include concepts like single- and double-resonant enhancement cavities, high power fibre amplification, dynamic spectral zooming, advanced modulation schemes and parallel designs.
The first part of the project addresses a comprehensive understanding of the underlying physical effects and how to increase the Raman signal by several orders of magnitude using these various strategies. The aim of the second part is to investigate, in how far these improved FDML based Raman systems can be applied to transient real time spectroscopy, analytical sensing, and Raman microscopy.
Summary
Raman spectroscopy is one of the most specific non-destructive optical techniques to identify the chemical composition of a sample. Further, there is great hope that in the future it may be a powerful biomedical imaging technique for in vitro or in vivo microscopy, providing molecular contrast without exogenous contrast agents.
However, due to the small Raman cross-section, for many applications the acquisition is prohibitively slow. Techniques to solve this problem and to increase the Raman signal levels are coherent anti-Stokes Raman spectroscopy (CARS), surface enhanced Raman spectroscopy (SERS) and stimulated Raman spectroscopy (SRS). However, in many cases, they are currently not able to provide rapid, highly sensitive detection of an undistorted signal with a broad spectral coverage.
The aim of the project is to investigate Fourier domain mode locked (FDML) lasers for the application to stimulated Raman detection. A variety of physical effects, unique to FDML lasers, enables strategies to substantially increase the Raman signal level. This can provide access to highly sensitive Raman spectroscopy and high speed Raman microscopy. The techniques to increase the detection sensitivity include concepts like single- and double-resonant enhancement cavities, high power fibre amplification, dynamic spectral zooming, advanced modulation schemes and parallel designs.
The first part of the project addresses a comprehensive understanding of the underlying physical effects and how to increase the Raman signal by several orders of magnitude using these various strategies. The aim of the second part is to investigate, in how far these improved FDML based Raman systems can be applied to transient real time spectroscopy, analytical sensing, and Raman microscopy.
Max ERC Funding
1 168 058 €
Duration
Start date: 2011-01-01, End date: 2015-12-31
Project acronym GenGeoHol
Project Non AdS holography and generalized geometric structures
Researcher (PI) Diego HOFMAN
Host Institution (HI) UNIVERSITEIT VAN AMSTERDAM
Call Details Starting Grant (StG), PE2, ERC-2016-STG
Summary Holography is by now a fundamental tool in the understanding of both strongly coupled conformal field theories (CFTs) and quantum theories of gravity. While holography in Anti de Sitter (AdS) space-times is rather well understood, we currently lack a basic picture of what it means in non-AdS space-times. Considering non-AdS space-times is an essential and urgent next step in the study of quantum gravity as we seem to live in a universe with a positive cosmological constant that is approaching de Sitter (dS) in the far future. Also, the near-horizon geometries of black holes are typically described by more exotic geometries that need to be understood on their own right.
I propose to address this and study the physics of holographic systems on non-AdS space-times and their connection to generalized geometric structures that naturally arise in these setups. In order do this I will use both conventional field theory techniques and new holographic tools, some of which I have developed recently.
The relevance of GenGeoHol is illustrated by universal properties of black holes, e.g. their area-law entropy. These are independent of AdS, pointing towards the existence of a more general holographic principle that generalizes the usual symmetries and geometric notions. A great deal of evidence has accumulated recently indicating that this is indeed the case. The physics of extremal black holes and non relativistic systems are clear examples.
GenGeoHol will impact a wide range of fields. As one moves away from AdS Einstein gravity, the dual quantum-field theories present different symmetries from that of usual relativistic systems. These systems couple naturally to generalized background geometries which are of intrinsic interest and key to a range of concepts extending from Newton-Cartan geometry in non-relativistic systems to higher-spin geometries for so-called W_N CFTs.
Given my experience and track record, I am uniquely positioned to attack this problem successfully.
Summary
Holography is by now a fundamental tool in the understanding of both strongly coupled conformal field theories (CFTs) and quantum theories of gravity. While holography in Anti de Sitter (AdS) space-times is rather well understood, we currently lack a basic picture of what it means in non-AdS space-times. Considering non-AdS space-times is an essential and urgent next step in the study of quantum gravity as we seem to live in a universe with a positive cosmological constant that is approaching de Sitter (dS) in the far future. Also, the near-horizon geometries of black holes are typically described by more exotic geometries that need to be understood on their own right.
I propose to address this and study the physics of holographic systems on non-AdS space-times and their connection to generalized geometric structures that naturally arise in these setups. In order do this I will use both conventional field theory techniques and new holographic tools, some of which I have developed recently.
The relevance of GenGeoHol is illustrated by universal properties of black holes, e.g. their area-law entropy. These are independent of AdS, pointing towards the existence of a more general holographic principle that generalizes the usual symmetries and geometric notions. A great deal of evidence has accumulated recently indicating that this is indeed the case. The physics of extremal black holes and non relativistic systems are clear examples.
GenGeoHol will impact a wide range of fields. As one moves away from AdS Einstein gravity, the dual quantum-field theories present different symmetries from that of usual relativistic systems. These systems couple naturally to generalized background geometries which are of intrinsic interest and key to a range of concepts extending from Newton-Cartan geometry in non-relativistic systems to higher-spin geometries for so-called W_N CFTs.
Given my experience and track record, I am uniquely positioned to attack this problem successfully.
Max ERC Funding
1 300 775 €
Duration
Start date: 2017-09-01, End date: 2022-08-31
Project acronym NUCLEAREFT
Project Nuclear Physics from Quantum Chromodynamics
Researcher (PI) Evgeny Epelbaum
Host Institution (HI) RUHR-UNIVERSITAET BOCHUM
Call Details Starting Grant (StG), PE2, ERC-2010-StG_20091028
Summary Explaining low-energy nuclear structure from Quantum Chromodynamics, the
underlying theory of the strong interaction, is one of the major
challenges in contemporary theoretical nuclear and particle physics.
What is needed is, on the one hand, a detailed quantitative understanding of the
interaction between baryons, the relevant effective degrees
of freedom for the problem at hand, based on Quantum Chromodynamics. On the
other hand, a microscopic description of strongly interacting baryons requires
reliable methods to deal with the quantum mechanical few- and many-body problems.
The proposed research addresses both of the two challenges aiming to
achieve a precise, quantitative description of nuclear forces and the
properties of light nuclei and hyper-nuclei firmly rooted in the symmetries of
Quantum Chromodynamics. These goals will be reached by using analytical
methods based on chiral effective field theory combined with large-scale
numerical simulations on high-performance computers.
Summary
Explaining low-energy nuclear structure from Quantum Chromodynamics, the
underlying theory of the strong interaction, is one of the major
challenges in contemporary theoretical nuclear and particle physics.
What is needed is, on the one hand, a detailed quantitative understanding of the
interaction between baryons, the relevant effective degrees
of freedom for the problem at hand, based on Quantum Chromodynamics. On the
other hand, a microscopic description of strongly interacting baryons requires
reliable methods to deal with the quantum mechanical few- and many-body problems.
The proposed research addresses both of the two challenges aiming to
achieve a precise, quantitative description of nuclear forces and the
properties of light nuclei and hyper-nuclei firmly rooted in the symmetries of
Quantum Chromodynamics. These goals will be reached by using analytical
methods based on chiral effective field theory combined with large-scale
numerical simulations on high-performance computers.
Max ERC Funding
1 165 864 €
Duration
Start date: 2011-01-01, End date: 2015-12-31
Project acronym POLAR
Project Polar Molecules: From Ultracold Chemistry to Novel Quantum Phases
Researcher (PI) Silke Ospelkaus
Host Institution (HI) GOTTFRIED WILHELM LEIBNIZ UNIVERSITAET HANNOVER
Call Details Starting Grant (StG), PE2, ERC-2010-StG_20091028
Summary The recent realization of ultracold ensembles of polar molecules close to quantum degeneracy has marked a milestone in atomic and molecular physics and physical chemistry. Molecules rotate and vibrate and therefore offer many more quantum degrees of freedom than their atomic counterparts. Polar molecules - with their permanent electric dipole moment interact via strong long-range and anisotropic interaction, which provides unique opportunities for control of chemical reactions and engineering of novel strongly-correlated quantum many-body systems.
In this research proposal, we plan to develop techniques to control molecular processes such as chemical reactions on the quantum level and experimentally establish polar molecules as novel strongly correlated quantum many-body systems. Key topics will be the strong dipolar interaction and quantum confinement when molecules are forced into restricted geometries. The experimental work will focus on quantum-degenerate gases of bi-alkali polar molecules in optical lattices. We plan to develop techniques to precisely tailor and control the interaction potential between polar molecules by means of external ac and dc electric fields. Together with versatile control over restricted geometries, this will supply us with a unique toolbox to control ultracold chemical reactions and to engineer a wide variety of strongly correlated quantum phases - ranging from phases arising in the context of the finite-range Hubbard Hamiltonian to self-assembling crystalline structures and chains. Polar molecular quantum gases have the potential to open new scientific frontiers and address long-standing questions for cold controlled chemistry and fundamendal questions in condensed matter physics.
Summary
The recent realization of ultracold ensembles of polar molecules close to quantum degeneracy has marked a milestone in atomic and molecular physics and physical chemistry. Molecules rotate and vibrate and therefore offer many more quantum degrees of freedom than their atomic counterparts. Polar molecules - with their permanent electric dipole moment interact via strong long-range and anisotropic interaction, which provides unique opportunities for control of chemical reactions and engineering of novel strongly-correlated quantum many-body systems.
In this research proposal, we plan to develop techniques to control molecular processes such as chemical reactions on the quantum level and experimentally establish polar molecules as novel strongly correlated quantum many-body systems. Key topics will be the strong dipolar interaction and quantum confinement when molecules are forced into restricted geometries. The experimental work will focus on quantum-degenerate gases of bi-alkali polar molecules in optical lattices. We plan to develop techniques to precisely tailor and control the interaction potential between polar molecules by means of external ac and dc electric fields. Together with versatile control over restricted geometries, this will supply us with a unique toolbox to control ultracold chemical reactions and to engineer a wide variety of strongly correlated quantum phases - ranging from phases arising in the context of the finite-range Hubbard Hamiltonian to self-assembling crystalline structures and chains. Polar molecular quantum gases have the potential to open new scientific frontiers and address long-standing questions for cold controlled chemistry and fundamendal questions in condensed matter physics.
Max ERC Funding
1 260 000 €
Duration
Start date: 2011-02-01, End date: 2017-01-31
Project acronym PRECISION
Project Precision measurements to discover new scalar and vector particles
Researcher (PI) Johannes ALBRECHT
Host Institution (HI) TECHNISCHE UNIVERSITAT DORTMUND
Call Details Starting Grant (StG), PE2, ERC-2016-STG
Summary The Standard Model of particle physics successfully describes all known particles and their interactions. However, questions like the nature of dark matter or the hierarchy of masses and couplings of quarks and leptons remain to be understood. Hence, one searches for new phenomena that will lead to a superior theory that can explain these questions. All such theories introduce additional quantum corrections. Decay rates of processes which are strongly suppressed in the Standard Model are highly sensitive to these corrections.
The LHCb experiment at CERN has recorded the world’s largest sample of beauty mesons. In the five years of this proposal, this sample will be enlarged by more than a factor of five. This sets an optimal environment for precision tests for new phenomena in strongly suppressed beauty decays.
This proposal aims to discover new scalar or vector particles in precision measurements of leptonic and semi-leptonic beauty decays. These new particles are not predicted by the Standard Model of particle physics, a potential discovery would mark the most important finding in High Energy Physics of the last decades. Some existing anomalies in flavour data can be interpreted as hints for the particles searched for in this proposal. Two classes of measurements are planned within this proposal: the complete scan of purely leptonic beauty decays which include flavour changing neutral current as well as lepton flavour violating modes. Lepton flavour universality is tested in loop decays through a novel inclusive strategy. All proposed measurements will advance the world’s knowledge significantly and have a large discovery potential.
Summary
The Standard Model of particle physics successfully describes all known particles and their interactions. However, questions like the nature of dark matter or the hierarchy of masses and couplings of quarks and leptons remain to be understood. Hence, one searches for new phenomena that will lead to a superior theory that can explain these questions. All such theories introduce additional quantum corrections. Decay rates of processes which are strongly suppressed in the Standard Model are highly sensitive to these corrections.
The LHCb experiment at CERN has recorded the world’s largest sample of beauty mesons. In the five years of this proposal, this sample will be enlarged by more than a factor of five. This sets an optimal environment for precision tests for new phenomena in strongly suppressed beauty decays.
This proposal aims to discover new scalar or vector particles in precision measurements of leptonic and semi-leptonic beauty decays. These new particles are not predicted by the Standard Model of particle physics, a potential discovery would mark the most important finding in High Energy Physics of the last decades. Some existing anomalies in flavour data can be interpreted as hints for the particles searched for in this proposal. Two classes of measurements are planned within this proposal: the complete scan of purely leptonic beauty decays which include flavour changing neutral current as well as lepton flavour violating modes. Lepton flavour universality is tested in loop decays through a novel inclusive strategy. All proposed measurements will advance the world’s knowledge significantly and have a large discovery potential.
Max ERC Funding
1 498 249 €
Duration
Start date: 2016-12-01, End date: 2021-11-30
Project acronym UNIC
Project Ultracold negative ions by laser cooling
Researcher (PI) Alban Kellerbauer
Host Institution (HI) MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV
Call Details Starting Grant (StG), PE2, ERC-2010-StG_20091028
Summary Laser cooling is a well-established technique for the creation of ultracold particle ensembles in beams or traps. Over the past 30 years, it has become an indispensable tool in atomic physics and has opened many exciting new research fields. Both in positive atomic ions and in neutral atoms, the valence electron is bound in a Coulomb potential. The resulting infinite series of excited states provides a wide choice of suitable cooling transitions in many ionic and atomic systems. Surprisingly, laser cooling of negative atomic ions has never been achieved. The binding of the valence electron in these systems is based on electron electron correlation effects, which drop off quickly as the excess electron is removed from the neutral core. Consequently, anions are easily neutralized and only a few of them have excited levels. When excited states do occur, they are usually sub-levels of the ground state, meaning that transitions between the ground and excited state are weak and laser cooling would take prohibitively long. However, only a few years ago, a strong transition between the ground state and an opposite-parity excited state was found in the negative osmium ion. With this discovery, the laser cooling of atomic anions has finally come into reach. High-resolution optical spectroscopy on negative osmium has been carried out by the applicant, confirming the existence of a potential laser cooling transition. The aim of the proposed project is the first-ever demonstration of atomic-anion laser cooling. Ultimately, laser-cooled atomic anions could be used to cool any other negative-ion species by confining them simultaneously in a trap. The proposed technique is therefore applicable to a wide range of research fields in which ultracold negative ions are required.
Summary
Laser cooling is a well-established technique for the creation of ultracold particle ensembles in beams or traps. Over the past 30 years, it has become an indispensable tool in atomic physics and has opened many exciting new research fields. Both in positive atomic ions and in neutral atoms, the valence electron is bound in a Coulomb potential. The resulting infinite series of excited states provides a wide choice of suitable cooling transitions in many ionic and atomic systems. Surprisingly, laser cooling of negative atomic ions has never been achieved. The binding of the valence electron in these systems is based on electron electron correlation effects, which drop off quickly as the excess electron is removed from the neutral core. Consequently, anions are easily neutralized and only a few of them have excited levels. When excited states do occur, they are usually sub-levels of the ground state, meaning that transitions between the ground and excited state are weak and laser cooling would take prohibitively long. However, only a few years ago, a strong transition between the ground state and an opposite-parity excited state was found in the negative osmium ion. With this discovery, the laser cooling of atomic anions has finally come into reach. High-resolution optical spectroscopy on negative osmium has been carried out by the applicant, confirming the existence of a potential laser cooling transition. The aim of the proposed project is the first-ever demonstration of atomic-anion laser cooling. Ultimately, laser-cooled atomic anions could be used to cool any other negative-ion species by confining them simultaneously in a trap. The proposed technique is therefore applicable to a wide range of research fields in which ultracold negative ions are required.
Max ERC Funding
1 115 970 €
Duration
Start date: 2011-07-01, End date: 2016-06-30
