NQCP Life in Quantum - Senior Scientist Nicolai Friis, TU Wien

The entanglement frontier – from entanglement certification to benchmarking fault-tolerant quantum computers

Quantum correlations between multiple parties are a central ingredient for many quantum technologies, with applications in quantum communication, quantum computation, and quantum metrology, amongst others. However, while multipartite entanglement is a generic feature of many-body systems and we are at what some researchers call the “entanglement frontier” where we are able to generate and precisely control highly complex quantum systems, unravelling the entanglement structure of a given quantum system is generally difficult, both in theory and in practice. This talk will first give an introduction to the different forms of entanglement between several parties. Then, focusing on genuine multipartite entanglement (GME), the talk discusses the phenomenon of superactivation: Two or more copies of a quantum state can be resources, where a single copy is not. After an overview of recent theoretical and experimental advances in studying GME superactivation, and the related challenges for the detection of GME in practical setups, the talk will then present recent work on certifying GME between logical qubits, and an outlook towards using logical GME as a benchmark for fault-tolerant quantum computers.