**Quantum simulation and few-qubit applications**

This research line addresses **applications of small and medium-sized qubit platforms** (10-100 qubits). In quantum simulation one uses such systems as analogue versions of quantum computers, allowing the study of problems in quantum chemistry and material science, among others. Few-qubit algorithms implemented on 50 or more qubits quickly become intractable for classical computers. This research line also addresses multi-qubit dynamics and quantum control, with applications in the design of quantum registers and in quantum many-body physics.

**Quantum information science**

This research line addresses the broad range of insights and questions that arise as soon as** information is processed according to the rules of quantum mechanics**. Reasoning based on quantum notions such as superposition and entanglement leads to applications in computer science, mathematics, logic and physics that do not always need an actual physical device. Some successful examples: an optimal algorithm for matrix multiplication, solving problems in operator algebras and functional analysis, and error-correcting codes. In the realm of physics, quantum information can be used in the study of non-locality, quantum thermodynamics, condensed matter systems, and even the structure of space-time itself.

**Cryptography in a quantum world**

This research line is double-edged. One edge, known as **post-quantum cryptography**, is the development of cryptography that is difficult to break for attackers armed with large quantum computers. The goals are to improve existing schemes for this, to develop new efficient quantum-safe protocols and to analyse attacks that can be run on large quantum computers. The other edge, known as **quantum cryptography**, is the design and investigation of protocols that solve cryptographic problems securely using quantum communication.

**Quantum algorithms and complexity**

**Which computational tasks are amenable to quantum speed-up?** This research line addresses this fundamental question and develops and investigates new quantum algorithms. This activity is focused on the many-qubit regime, where full-fledged error correction and fault tolerant computation becomes possible. Important research questions are the verification and debugging of quantum algorithms – the very nature of quantum computing preempts methods known from classical computer science and calls for fundamentally new strategies and protocols.