Nadir Samos Sáenz de Buruaga: About barren plateaus and quantum complexity | PYSQT

Seminar by Nadir Samos Sáenz de Buruaga, organized by the PYSQT (PhDs and Young Scientists Quantum Technologies) network on the 20-12-2022. About barren plateaus and quantum complexity - I will review the barren plateaus (BPs) issue in the field of variational quantum algorithms (VQA) with a particular focus on those generated by an excess of randomness, providing an accessible introduction to the topic. I will also show that restricting the entanglement of the states seems not to be a good strategy for avoiding BPs, posing the question if there is another more decisive quantity that can help in this pursuit. I will then briefly introduce the quantum complexity and its relation, at least at a formal level, with the concept of expressibility of an ansatz. https://doi.org/10.1103/PhysRevB.104....