Caroline de Groot: Fundamental properties of SPT phases discovered
Focusing on so-called symmetry-protected topological (SPT) phases, Caroline de Groot uncovered some essential but previously unknown properties. Her findings further our understanding of STP phases in open systems.
Caroline de Groot pursued her PhD project as a member of the MPQ Theory division. Her work, supervised by Norbert Schuch, interweaves the fields of quantum information and quantum many-body systems. Specifically, she investigated how topological phases are affected by a noisy environment. Since her graduation, Caroline de Groot moved on to work as a Quantum Software Engineer at Pasqal. Our warmest congratulations!
In her research project, Caroline de Groot wanted to understand how certain exotic quantum phases of matter – generally known as topological phases – are affected in the presence of a noisy environment. She focused her research on a specific class of topological phases which is furthermore characterised by the presence of symmetry. Consequently, the young theorist discovered some previously unknown fundamental properties of SPT phases. Her results help us understand, in particular, how allowing a system in a certain phase to interact with an environment impacts its fundamental properties.
As an integral part of her research, she used so-called tensor networks as a framework. Tensor networks are a helpful theoretical tool which allows the analytical and numerical study of several particular properties of these phases – such as entanglement and structures relating to entanglement, but also characteristic order parameters whose values uniquely determine a phase.
Caroline de Groot showed that symmetry-protected topological phases have a certain amount of “protected” entanglement. She furthermore proved that symmetry-protected phases are robust only in open systems which obey strong symmetries. These findings are important because they provide an initial framework for these phases for mixed states. Her research is therefore a first step towards developing a full picture of symmetry-protected phases in open systems.
PhD Survival Tips - #1 Caroline de Groot
Her research aside, Caroline de Groot also enjoyed her time at MPQ both for the people and the experiences: “I made lifelong friendships here, sharing many dinners, housemate moments, and weekend study support sessions,” she explains. Memorable moments from her PhD time include a karaoke party at MPQ’s h-bar and teaching a salsa and swing dance workshop at the Benasque conference.
Caroline has begun a position as Quantum Software Engineer at the company Pasqal based in Paris in December 2022, with a focus on the simulation of quantum dynamics and quantum circuits using her background in quantum computing and tensor networks.