6 PhD positions are available within the context of our NL-eEDM research program. We use cold molecules to probe fundamental physics - specifically the electron’s electric dipole moment (EDM). We are looking for motivated PhD students with a strong interest the relevant fields of physics. The experiment is set up at the Van Swinderen Institute (VSI) at the University of Groningen in The Netherlands. The NL-eEDM program is a collaboration of the University of Groningen, Vrije University Amsterdam, University of Amsterdam. The program is part of the research mission of Nikhef, which is the Dutch national institute for subatomic physics. PhD position 3 is at the VU in Amsterdam, all others are at the VSI Groningen.
A brief description of the specific projects (with the main supervisor, whom you can contact for more details) is given below.
PhD position 1: A bright and cold beam of slow molecules (Steven Hoekstra)
The sensitivity of the measurements to the electron’s EDM is increased when using slowly moving molecules. In this subproject we make use a combination of cooling techniques to form a bright and slow molecular beam for eEDM measurements.
PhD position 2: Spin interferometer and data analysis (Lorenz Willmann)
In this subproject we focus on the all-optical state preparation, spin precession and the readout. In particular the dependence of the EDM sensitive signal on the experimental parameters such as laser intensities, detunings and polarizations will be characterised. The measurement cycle will be implemented to separate experimental asymmetries from the CP-violating eEDM and provide for a blind analysis.
PhD position 3: A fountain of BaF molecules (Rick Bethlem)
A lens / mirror / cooling system based on electric fields and resonant light will be designed and constructed that will deflect a Stark decelerated molecular beam upwards in a fountain. The system should allow continuous operation. The system will be tested and optimized using a slow beam of MgF molecules before applying it to BaF.
PhD position 4: Polyatomic molecules (Steven Hoekstra)
We have recently demonstrated the deceleration and electrostatic trapping of the heavy diatomic neutral molecule SrF. This approach is general: it does not rely on a closed optical cycle and can therefore be applied to many molecules. We will apply this technique to eEDM-sensitive polyatomic molecules. Polyatomic molecules are promising for eEDM measurements since they offer internal co-magnetometers and can be completely polarized at relatively low electric fields.
PhD position 5: Theory of complex molecules in external fields (Anastasia Borschevsky)
We will perform high accuracy relativistic coupled cluster calculations of key properties of the polyatomic molecules. Knowledge of these properties is crucial for determining the best experimental strategy. In parallel, we will use approximate computational methods (relativistic DFT) to scan the vast and varied landscape of small (3-7 atoms) polyatomic molecules in the search for further promising candidates for measurements.
PhD position 6: An effective field theory framework (Jordy de Vries)
The impressive progress in EDM searches with polar molecules requires a new theoretical framework that goes beyond the interpretation in terms of only the electron EDM. We will construct an effective field theory framework to interpret the BaF measurements in terms of fundamental CP-violating operators. We will not only include CP-odd effects among the nucleons and electrons that constitute the BaF molecule, but also leptonic, semi-leptonic, and hadronic CP-violating operators involving heavier fundamental fields (such as muons, top quarks, and Higgs bosons) that contribute through quantum loop effects.
More experienced candidates interested in a postdoc position (on theory or experiment) are also invited to contact us to discuss opportunities.
For the experimental PhD positions 1-4 we have a joint application procedure, which can be accessed through the following link: xxxxx
For PhD positions 5 and 6, interested candidates can apply through xxxxx and xxxxx.
A brief description of the specific projects (with the main supervisor, whom you can contact for more details) is given below.
PhD position 1: A bright and cold beam of slow molecules (Steven Hoekstra)
The sensitivity of the measurements to the electron’s EDM is increased when using slowly moving molecules. In this subproject we make use a combination of cooling techniques to form a bright and slow molecular beam for eEDM measurements.
PhD position 2: Spin interferometer and data analysis (Lorenz Willmann)
In this subproject we focus on the all-optical state preparation, spin precession and the readout. In particular the dependence of the EDM sensitive signal on the experimental parameters such as laser intensities, detunings and polarizations will be characterised. The measurement cycle will be implemented to separate experimental asymmetries from the CP-violating eEDM and provide for a blind analysis.
PhD position 3: A fountain of BaF molecules (Rick Bethlem)
A lens / mirror / cooling system based on electric fields and resonant light will be designed and constructed that will deflect a Stark decelerated molecular beam upwards in a fountain. The system should allow continuous operation. The system will be tested and optimized using a slow beam of MgF molecules before applying it to BaF.
PhD position 4: Polyatomic molecules (Steven Hoekstra)
We have recently demonstrated the deceleration and electrostatic trapping of the heavy diatomic neutral molecule SrF. This approach is general: it does not rely on a closed optical cycle and can therefore be applied to many molecules. We will apply this technique to eEDM-sensitive polyatomic molecules. Polyatomic molecules are promising for eEDM measurements since they offer internal co-magnetometers and can be completely polarized at relatively low electric fields.
PhD position 5: Theory of complex molecules in external fields (Anastasia Borschevsky)
We will perform high accuracy relativistic coupled cluster calculations of key properties of the polyatomic molecules. Knowledge of these properties is crucial for determining the best experimental strategy. In parallel, we will use approximate computational methods (relativistic DFT) to scan the vast and varied landscape of small (3-7 atoms) polyatomic molecules in the search for further promising candidates for measurements.
PhD position 6: An effective field theory framework (Jordy de Vries)
The impressive progress in EDM searches with polar molecules requires a new theoretical framework that goes beyond the interpretation in terms of only the electron EDM. We will construct an effective field theory framework to interpret the BaF measurements in terms of fundamental CP-violating operators. We will not only include CP-odd effects among the nucleons and electrons that constitute the BaF molecule, but also leptonic, semi-leptonic, and hadronic CP-violating operators involving heavier fundamental fields (such as muons, top quarks, and Higgs bosons) that contribute through quantum loop effects.
More experienced candidates interested in a postdoc position (on theory or experiment) are also invited to contact us to discuss opportunities.
For the experimental PhD positions 1-4 we have a joint application procedure, which can be accessed through the following link: xxxxx
For PhD positions 5 and 6, interested candidates can apply through xxxxx and xxxxx.
