PhD and postdoc positions in molecular-ion quantum technologies

PhD and postdoc positions are available in our group on the development of quantum technologies for single trapped molecular ions.

Project description

In recent years, impressive advances in the quantum control of ultracold atoms and atomic ions have been achieved which enabled measurements with an unprecedented precision. Similarly precise experiments on molecules open up a range of new scientific perspectives including tests of new physical concepts, the implementation of new frequency standards, accurate evaluations of physical theories such as quantum electrodynamics and precise determinations of fundamental constants. They also lay the foundations for applications of molecules in the realm of modern quantum science such as quantum information and quantum sensing.  

We have recently developed a new experimental approach enabling the readout of the quantum state of a single trapped molecular ion without destroying the molecule and indeed its quantum state itself. In the present project, the potential of this new method will be harnessed to perform highly sensitive and precise spectroscopic measurements on single moelcules. In the project, we will introduce completely new methods for molecular spectroscopy, further develop quantum technologies for molecular systems and establish new limits for the measurement precision of trapped molecules. 

Further information and applications

For further information, please refer to recent publications, e.g.,

M. Sinhal and S. Willitsch, "Molecular-ion quantum technologies", arXiv:2204.08814
M. Sinhal et al., "Quantum non-demolition state detection and spectroscopy of single trapped molecules”, Science 367 (2020), 1213 
K. Najafian et al., "Identification of molecular quantum states using phase-sensitive forces”, Nat. Commun. 11 (2020), 4470

or contact Prof. Stefan Willitsch. Candidates for the PhD positions should have a MSc degree in physics or physical chemistry, preferably with experience in experimental quantum science, quantum optics or spectroscopy. The PhD positions will be embedded in the Basel PhD program on “Quantum Computing and Quantum Technology” (QCQT, and be part of the Basel Quantum Center (

Candidates for the postdoc position should have a PhD in quantum science, quantum optics or atomic/molecular physics, preferably with a background in ion trapping.  

Inquiries and applications should be sent to Prof. Stefan Willitsch ( and include a cover letter, a curriculum vitae, a list of publications, transcripts of degree certificates and the contact details of at least two referees. 

PhD position: Conformationally Controlled Chemistry in the Gas Phase

A PhD position is available within our controlled chemistry research programme. The project aims at controlling and exploring the role of individual molecular conformations on the chemical reactivity and dynamics of reactions in the gas phase. 

Project description

The relationship between structure and reactivity is one of the central tenets of chemistry. In spite of the long history of inquiries into this problem, there is still a glaring lack of experimental data on structure-reactivity relationships studied under single-collision conditions. In particular, complex molecules possess multiple conformers (rotational isomers) that interconvert through hindered rotations about covalent bonds. It is well established that the molecular conformation can have a pronounced influence on the chemical reactivity. However, in room-temperature solution- or gas-phase experiments, conformers usually interconvert into one another through thermal motion leading to mixtures in which all specificity is lost. 

The present PhD project will employ new experimental methods developed by our group for studying chemical reactions of individual conformers prepared by electrostatic deflection in the gas phase. Such gas-phase studies are the cleanest and most accurate approach to disentangle different aspects contributing to chemical reactivity and are, therefore, vital for understanding the microscopic details of chemical processes. The present studies will focus on reactions of specific conformations of prototypical organic molecules with conformationally selected molecular ions in order to gain an in-depth understanding of fundamental aspects of conformer-specific reactivity in selected model systems. 

Further information and applications

For further information, please refer to recent publications, e.g.,

A. Kilaj, J. Wang, P. Straňák, M. Schwilk, U. Rivero, L. Xu, O. A v. Lilienfeld, J. Küpper, and S. Willitsch, "Conformer-specific polar cycloaddition of dibromobutadiene with trapped propene ions", Nat. Commun. 12 (2021), 6047
L. Ploenes, P. Straňák, H. Gao, J. Küpper and S. Willitsch, ”A novel crossed-molecular-beam experiment for investigating reactions of state- and conformationally selected strong-field-seeking molecules”, Mol. Phys. 119 (2021), e1965234
A. Kilaj, H. Gao, D. Rösch, U. Rivero, J. Küpper and S. Willitsch, "Observation of different reactivities of para- and ortho-water towards trapped diazenylium ions", Nat. Commun. 9 (2018), 2096

Further inquiries and applications should be sent to Prof. Stefan Willitsch ( Candidates should have (or soon obtain) a masters degree in physical chemistry, atomic/molecular/chemical physics or a related field. Applications should include a curriculum vitae, transcripts of degree certificates and grades, a letter of motivation and the contact details of at least two referees.

PhD position: Laboratory astrochemistry controlled with electromagnetic fields

A PhD position is available with Dr Jutta Toscano to investigate how molecular complexity in interstellar space emerges from the reaction of small atomic and molecular fragments. The combined use of electric fields, magnetic fields and laser light enables the precise control of the velocity and quantum state of the reacting species to understand the fundamental reaction dynamics of astrochemical processes. In this project, the effect of adding a single quantum of rotational excitation on the reaction kinetics and products will be explored.

Highly-motivated candidates who have (or will soon obtain) a Master’s degree in physical chemistry, atomic/molecular/chemical physics or a related field are encouraged to contact Dr Toscano via email ( for both informal enquiries and official applications. To apply, please send a CV, motivation letter, transcript of degree certificates and grades, as well as the contact details of at least two referees. The starting date of the project is flexible.


Relevant publications:

J. Toscano, H. J. Lewandowski and B. R. Heazlewood, “Cold and controlled chemical reaction dynamics”, Phys. Chem. Chem. Phys., 22, 9180 (2020)

A. Kilaj, H. Gao, D. Rösch, U. Rivero, J. Küpper and S. Willitsch, “Observation of different reactivities of para and ortho-water towards trapped diazenylium ions”, Nat. Commun., 9, 2096 (2018)

Undergraduate projects, master theses, PhD and postdoc positions

We are always looking for new members to join our group. If you are interested in an undergraduate project (Wahlpraktikum) or master thesis in our group, or would like to join as a Ph.D. student or postdoc, please contact Stefan Willitsch. We offer a vibrant and friendly research atmosphere in an exciting, highly interdisciplinary scientific field at the interface between chemistry and physics, the possibility to participate in international research collaborations, state-of-the-art laboratories and an excellent infrastructure.
Candidates should have degrees in chemistry or physics. Applications for PhD and postdoc positions should include a curriculum vitae, a letter of motivation, the contact details of at least two referees and a list of publications. PhD applicants should also include transcripts of their academic records.