Markus Müller (RWTH Aachen und Forschungszentrum Jülich) - Fault-Tolerant Quantum Computers: Progress and Perspectives


Quantum computers hold the promise to efficiently solve some computa5onally hard problems, for which efficient solu5ons are intractable on classical computers. Unfortunately, unavoidable noise limits the capabili5es of current so-called noisy intermediate-scale quantum (NISQ) devices. To date, the construc5on of scalable fault-tolerant quantum computers remains a fundamental scien5fic and technological challenge. In my talk, I will first introduce basic concepts of quantum compu5ng, review some of the promising applica5ons, and then outline concepts from quantum error correc5on. The laGer approach allows one to protect quantum informa5on during storage and processing by redundant encoding of informa5on in logical qubits formed of mul5ple physical qubits. I will discuss recent theory work, perspec5ves and recent collabora5ve experimental breakthroughs towards fault-tolerant quantum error correc5on on various physical quantum compu5ng plaIorms. This includes the first realisa5ons of repeated, high-performance quantum error-correc5on cycles on topological error correc5ng codes with superconduc5ng qubits, and the first execu5on of universal and fault-tolerant logical quantum gates with trapped ions. Furthermore, I will highlight alterna5ve explora5ve approaches towards robust quantum processors, based e.g. on quantum machine-learning based concepts, and outline some promising pathways to scale up current systems towards scalable, errorcorrected quantum processors.