The 33rd Chris Engelbrecht Summer School, titled “Theoretical Foundations of Quantum Science and Quantum Technologies”, took place at the Stellenbosch Institute for Advanced Study (STIAS) from 7 – 14 April 2025. The school was organised by Prof Francesco Petruccione and Dr Graeme Pleasance, both of whom are experts in the field of open quantum systems.
Students from across the country took part in an intensive week of study, learning the foundations of open quantum systems theory, as well as learning applications of this theory in contexts ranging from quantum thermodynamics to quantum biology. Lectures were given by top international researchers, who travelled from as far afield as Japan and Canada.
The school opened with a rigorous mathematical introduction to open systems theory by Prof Marco Merkli from the Department of Mathematics and Statistics at Memorial University of Newfoundland, located in St. John’s, Canada. His research is primarily focused on the analysis and understanding of open quantum systems – quantum systems that interact with their external environments. His work plays a key role in bridging the gap between mathematics and physics, with application to quantum information theory and quantum thermodynamics.
Conference organiser, Dr Graeme Pleasance, took up where Marco left off by addressing the formal characterisation of memory effects in open quantum systems, focusing on several definitions of quantum non-Markovianity. His current research focuses on developing nonperturbative techniques for simulating the dynamics of open quantum systems, particularly in regimes where memory effects are significant.
Dr Camille Lombard Latune introduced the basic concepts of quantum thermodynamics within the formalism of open quantum systems. Camille is a former postdoctoral researcher from Prof Petruccione’s group who is now based at the University of Burgundy, France. His work is focused on integrating quantum mechanics with thermodynamics and what novel resources quantum effects might offer classical thermodynamic concepts.
A philosophical approach
In addition to mathematical physics approaches, the school included a more philosophical approach to understanding quantum theory. Dr Ahsan Nazir, leader of the Manchester Noisy Quantum Systems Group at the University of Manchester presented a stimulating overview of the different interpretations of quantum mechanics from the measurement problem to the possibility of many worlds.
The school also featured a computational focus, with Dr Neill Lambert (Theoretical Quantum Physics Laboratory at RIKEN in Japan) outlining exciting new additions to the Quantum Toolbox in Python (QuTiP), of which he is a developer. QuTiP is a powerful computational tool for modelling quantum systems, and Neill presented some of the contexts to which it can be applied, including examples from quantum biology.
Prof Menica Dibenedetto extended this computing theme to an introduction of basic concepts in quantum artificial intelligence. Menica coordinates the Quantum Computing Research Team at Maastricht University, and her research focuses on Quantum AI, exploring both classical AI for quantum computing and quantum computing for AI. The students were encouraged to investigate how their new knowledge of open quantum systems theory might be applied to quantum machine learning.
Practical application
As the week progressed, lectures moved from theoretical modelling to practical application, with Prof Barry Garraway, from the University of Sussex in the UK, presenting the theory and application of new types of traps for ultra-cold atoms. This included a fascinating discussion on atom traps in zero gravity and how these experiments are conducted on the International Space Station.
Finally, Dr Towan Nöthling (University of Pretoria) gave a series of lectures on the application of open quantum systems to quantum biology. He focused mainly on the interaction of light and biological systems that gives rise to photosynthesis, while also outlining the theoretical and experimental aspects of spectroscopy. He finished his lectures with a broader overview of exciting emerging research in quantum biology, including questions about consciousness itself.
At the end of the week there was enthusiastic agreement from both students and lecturers that the school had been an enjoyable experience with much being learnt.