# Research

### Our group strives to understand the nonclassical phenomena featured in Nature, and how to harness their power to enable new forms of information processing.

- Discovering a theory beyond quantum

To date, it still remains unclear whether Quantum theory is the ultimate theory of Nature, one main reason for this being the tension it displays with the theory of General Relativity. If quantum theory is replaced in the future, what can we expect from the new physical theory that will take its place? When quantum theory emerged, we were taken by surprise: can we prepare ourselves this time? Here we explore the possibilities of a physical theory beyond quantum theory; that is, we search for physical theories that may supersede quantum. We study whether such a theory can be conceived, and, if so, which apparently fundamental quantum features must be abandoned.

- Characterising quantum phenomena

It is well known that quantum systems can be correlated in a way that is stronger than classically allowed. But how strong can those correlations be? Can we quantify this in a way that tells us how useful the correlations are to perform secure cryptography? This is just an example of a broad list of questions, all which aim at the following open questions that we tackle here:

- how to generate an intuitive understanding of the statistical predictions of quantum theory, which would help us devise technological applications,

- and how to quantify such non-classicality in a way that measures the quantum advantage.

- Harnessing nonclassicality for information processing

Nonclassical features of quantum theory enable information processing, such as cryptography and quantum computing, beyond our classical capabilities. New discoveries in the field of quantum foundations bring constantly new insight on new properties of Nature that we could exploit. Examples of these are Indefinite causal order, and generalised Contextuality. Here we explore how these new phenomena can be used to power technological developments.

- Developing the foundations for quantum software

Implementations of quantum computers have been extensively researched in the past. However, the development of high-level quantum software, a crucial aspect pertaining to quantum computing, is still not fully mastered. Here we work on improving the foundations in which quantum software will be developed in the future. We aim to leverage the versatility of the so-called zx-calculus to tackle basic questions about quantum computation, which include the identification of the source of speed-up in quantum computing.