Research interests

• Ultrafast Dynamics
• Quantum Computing 
• Quantum Chemistry

Current research

My research focuses on and combines computational chemistry and quantum computing. Therein, specific interest lies in (quantum) algorithm development and study of nuclear and electron dynamics crucial to Photochemistry and Attosecond Science/Chemistry.

Ultrafast Dynamics

The ability to measure the dynamics of electrons and nuclei is essential to improve understanding of light-induced processes, to advance industrial and medical applications, and to develop new technologies and materials that exploit quantum effects. In the last decades, novel light sources have created ever shorter light pulses that revolutionised scientists’ ability to study rotational and nuclear dynamics for photochemistry and brought about the emergence of a new research area known as attosecond science that – for the first time – allows access to the time scale of electronic wave packets. Utilizing the 2023 Nobel prize winning attosecond technology to understand, monitor, and one-day control the movement of electrons on their native attosecond timescale will open a new pathway to steer nuclear dynamics and photochemical reactions and is strongly associated with a new approach to photochemistry.

In my research, I (i) employ the whole range of quantum chemical and quantum dynamical methods to study nuclear dynamics and excited states with their properties, (ii) look outward to the possibilities that attosecond science and the study of electron dynamics pose for photochemistry, and (iii) combine dynamics with quantum computing to prepare dynamics algorithms for future computing technology (see below).

Selected Publications:

• doi.org/10.1038/s41566-024-01436-9
• doi.org/10.3389/fchem.2022.942633
• doi.org/10.1088/1361-6455/acc4fa

Quantum Computing for Chemistry

Quantum computing is poised to be the next big emerging technology with the potential to fundamentally change our capabilities to model materials and thus impact discoveries in chemistry, physics, and biology. The necessity to completely re-think our algorithm design and adapt to new architecture operating around superposition and entanglement makes it a fascinating and fast-evolving field of study.

Computational chemistry could be one of the first applications to demonstrate quantum advantage on quantum computers and thus bring significant impact beyond academia. On a quantum computer, its smallest building blocks (qubits) exhibit quantum mechanical properties, like superposition and entanglement, which – in principle – allow mapping the exponentially increasing configuration space of molecules to a linearly scaling number of qubits. This opens the simulation of large multi-configurational systems at the highest level of theory which would revolutionize simulations from material design to drug discovery with unprecedented impact on research and industry.

In my research, I develop quantum algorithms enabling molecular simulations on quantum computers. This includes (i) wave function optimization, (ii) molecular properties in ground and excited states, (iii) quantum and semi-classical dynamics (see above), and (iv) chemistry-focused error mitigation schemes.

Selected publications:

• doi.org/10.48550/arXiv.2408.09308
• doi.org/10.1021/acs.jctc.3c01402
• doi.org/10.1021/acs.jctc.4c00574

Karl Michael Ziems studied chemistry and theoretical chemistry at the Friedrich Schiller University Jena (Germany) and the University of Oxford (UK), respectively, before obtaining his PhD within the Max Planck School of Photonics (Germany) in theoretical chemical physics. His thesis entitled “High-frequency light-matter interaction in atoms and molecules” focused on understanding ultrafast nuclear and electron dynamics, as well as aiding experimental studies within attosecond science and femtochemistry. Before joining Southampton as a Lecturer, Karl Michael worked as postdoctoral researcher at the Technical University of Denmark within the project “Hybrid Quantum Chemistry on Hybrid Quantum Computers” (HQC2). He has also undertaken research stays at the Max Planck Institute for Chemical Energy Conversion, King Abdullah University of Science and Technology, and the University of Edinburgh.