Quantum Error Correction is a key element of unlocking the potential of quantum computers, providing the only way to run deep quantum circuits on noisy hardware, yet still obtain reliable results. The development of quantum error correcting codes is a rapidly evolving field, where concepts from statistical physics, condensed-matter physics, computational science and mathematics come together. Interestingly, topological concepts play important roles in the currently leading quantum error correction protocols, such as the surface code and the color code. The theoretical concepts also need to be adapted to the strengths and limitations of the various hardware implementations, such as superconducting nanocircuits or vacuum-levitated neutral atoms. The PhD research of the applicant will aim to further develop such quantum error correction protocols, and their use for quantum computation (also known as fault-tolerant quantum computation), and explore how well they fit to current hardware, using theoretical modeling and computer simulations. This research will be carried out in an international network of leading European research organisations in the framework of the OpenSuperQPlus Horizon Europe project.