Project Summaries
1. AI-Controlled Laser Platforms for Quantum Sensing (Quantum Sensing)
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Title: Integrate AI-control with a laser platform for quantum sensing experiment |
Advisor: Xing Wu (FRIB) |
Topic: Instrumental developments, experimental analysis |
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Summary: Quantum metrology has become increasingly precise in probing fundamental laws of physics, especially with the recent experimental breakthroughs that transform atoms and molecules into quantum sensors. However, for decades it has remained a formidable challenge to protect such quantum sensors against environmental noise, system drift, and imperfections in the experimental control. In this project, we aim to integrate physics-informed learning and reinforcement learning into a closed-loop and autonomous control of a laser platform, which will be used in our quantum metrology experiment. |
2.Precision Spectroscopy with lasers for New Physics (Fundamental Symmetries)
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Title: Precision laser spectroscopy of ThO molecules for testing fundamental symmetries |
Advisor: Xing Wu (FRIB) |
Topic: Instrumental developments, experimental analysis |
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Summary: Measurements of the electric dipole moment (EDM) of fundamental particles place the most stringent constraints on time-reversal-violating new physics beyond the Standard Model. Precision spectroscopy on cold 232ThO neutral molecules provides one of the best bounds on the electron electric dipole moment. In addition, 227,229ThO neutral molecules provide an excellent opportunity to search for the nuclear Schiff moment. In this project, the student will be developing the laser and optics system for performing precision spectroscopy measurements on cold ThO molecules. The project will also involve development of the vacuum beamline and cryogenic system necessary to produce the ThO molecules. |
3. Ultra-cold regime for Symmetry Tests (Precision Metrology)
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Title: Centrifuge decelerator of radioactive molecules & atoms for fundamental symmetry tests |
Advisor: Xing Wu (FRIB) |
Topic: Instrumental developments, experimental analysis |
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Summary: Precision metrology on atoms and molecules benefits tremendously when the particles are prepared in the ultracold regime. This enables control and detection of atoms or molecules at the single-quantum-state level. In this project, we are developing a unique method to decelerate radioactive atoms and molecules to a standstill by centrifugal force. A spinning magnetic guide will be used to guide neutral atomic/molecular species from the periphery to the center of the rotating frame, and an electromagnetic trap will be used to collect the decelerated particles after they exit the centrifuge decelerator. This work will open the avenue to precision spectroscopy of superheavy species like Radium or Thorium containing molecules, as well as light species like Tritium atoms. |
4. Nucleon transfer reaction and uncertainty (Nuclear Theory)
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Title: Charge Exchange Reactions with the Nuclear Shell Model |
Advisor: Filomena Nunes (FRIB) and Chloe Hebborn (IJCLab Orsay) |
Topic: Nuclear Reactions |
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Summary: The equation of state (EoS) of dense matter governs the structure, composition, and stability of neutron stars. Among the least understood terms of the nuclear EoS is the isovector dependence of the symmetry energy. Charge exchange reactions, which occur when a proton collides with a target nucleus, gets absorbed, and emits a neutron, are important for constraining this dependence. Within a recently developed framework, such reactions can be directly computed from microscopic many-body predictions, treating both structure and reactions on equal footing. In this project, the student will analyze isotopic chains of both Mg and Ca. They will generate, using the microscopic shell models, all relevant spectroscopic amplitudes up to a few MeV above the proton threshold. This includes all compound, compound-minus-neutron, and compound-minus-proton amplitudes. They will extend the formalism, improving the single-particle description of the resonant parameters to proton states. They will combine the single-particle and many-body contributions within the microscopic S-matrix framework to extract cross sections and compare with experiment when available, as well as make predictions where no data exists. The latter can act as a motivation for future experiments |
5. Physics-informed machine learning and emulators
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Title: Surrogate models for linear response in finite nuclei |
Advisor: Witold Nazarewicz, Pablo Giulian (FRIB) and Elias Khan (IJCLab Orsay) |
Topic: Many-body nuclear theory |
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Summary: The collective excitation of nuclear systems close to their ground-state is very well described with the linear response theory, which is a well-established method in physics and chemistry. In particular, the quasiparticle random-phase approximation (QRPA) provides a powerful microscopic framework by building excitations on top of the mean-field vacuum; however, its high computational cost limits model calibration and uncertainty quantification studies. We have explored two complementary QRPA surrogate models and applied them to study response functions of finite nuclei. One is a reduced-order model that exploits the underlying QRPA structure, while the other utilizes the recently developed parametric matrix model algorithm to construct a map between the system's Hamiltonian and observables. Both emulators can achieve 0.1\%--1\% accuracy while offering a six to seven orders of magnitude speedup compared to state-of-the-art QRPA solvers. The QRPA emulators are well-positioned to enable Bayesian calibration and large-scale studies of computationally expensive physics models describing the properties of many-body systems. |
6. Equation of State (EOS) of Nuclear Matter
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Title: Heavy Ion Collisions from nuclear physics to astrophysics |
Advisor: Oleh Savchuk (IRL-NPA), and Joerg Aichelin, (SUBATECH Nantes) |
Topic: Heavy-ion collision |
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Summary: We are a group specializing in the dense nuclear matter theorized to compose neutron stars and created in laboratories by colliding two heavy nuclei. The project aims to understand how pressure builds under these extreme conditions, with densities beyond those found in atomic nuclei, by providing a theoretical description of data from both terrestrial experiments and various astronomical observations. To that end, light nuclear fragments are important constituents of dense matter that require refined modeling. Potentially formed at the late stages of heavy-ion reactions or found in the crusts of neutron stars, they impact our ability to infer the correct behaviour of the pressure. By treating clustering in a heavy-ion collision, you will have the opportunity to advance the field by applying expertise in theoretical physics, data-driven modeling, software engineering and scientific computing, while collaborating with the research communities at Subatech, France, and the Facility for Rare Isotope Beams, USA. |