Meet the FoQaCiA partners: ICTQT at University of Gdańsk

Gdansk’s ICTQT FoQaCiA PIs Dr. hab. Ana Belén Sainz and Dr. John H. Selby.

The ICTQT node of FoQaCiA is led by the PIs Dr hab. Ana Belén Sainz and Dr John H. Selby, and its main scientific contributions pertain to work package WP1 on Quantum contextuality, non-classicality, and quantum advantage. The team currently includes two FoQaCiA-funded postdocs: Vinicius Pretti Rossi and Roberto Dobal Baldijão, as well as Dr Beata Zjawin from ICTQT. Our research focuses on the foundations of quantum theory, exploring notions of nonclassicality and how they can be leveraged for quantum advantage. We are especially devoted to understanding how generalized contextuality, a gold standard concept of nonclassicality, can be used as a resource in quantum technologies. The group is also interested in probabilistic theories that are more general than quantum theory, focusing on what we can learn about quantum theory by comparing with these broader counterparts.

Some of our recent contributions we’d like to highlight include :

-The development and application of open-source numerical tools for assessing generalised contextuality in prepare-and-measure experiments in quantum communication tasks and its robustness to noise, which is essential for practical applications in which some noise is always present. (Phys. Rev. A 108, 032213 and https://arxiv.org/abs/2406.12773 -- in press at Phys. Rev. A.)

- The development of a linear program to test generalized contextuality in scenarios involving a transformation, including the first noncontextuality inequality to be violated by quantum stabilizer systems due solely to the nonclassicality of transformations allowed by quantum systems. (https://arxiv.org/abs/2407.09624)

- A generalization of an important representation of quantum states -- named Kirkwood-Dirac distributions, that carry broad applications in recent quantum information literature --  that now can be used for representing also channels and measurements. We also find connections to generalized contextuality, thus deciding when such a representation signals (non)classicality of quantum processes. (https://arxiv.org/abs/2405.04573)

- An analysis of how the superposition of causal orders by the use of the so-called quantum-SWITCH can be affected due to environmental interactions -- and when quantum phenomena can be shielded from such uncontrolled environmental interactions  (Comm. Phys. 7, Article number: 373, https://www.nature.com/articles/s42005-024-01843-y).

- An investigation of how assessments of generalized contextuality in prepare-and-measure experiments can be mistaken or still correct when one does not have access to full tomography -- that is, when one might not have access to all possible states or measurements in a generalized probabilistic theory. This clarifies how to not accidentally confuse lack of tomography with a possible advantage over classical implementations, hence enabling a robust exploration of nonclassicality in a prepare-and-measure experiment. (https://arxiv.org/abs/2409.13024)