Quantum advantage with superconducting quantum circuits: from sensing to computing

by Prof. Martin Weides (University of Glasgow)

Friday 10 Jan 2020, 12:00 → 13:30 Europe/Madrid

IFAE seminar room (IFAE)

Quantum technology receives considerable attention from the academic and commercial sector, as well as from the media. Non-classically interacting states of qubits play a central role in quantum technology, from Bell states to quantum annealing & simulation to achieving a quantum advantage in computing. Today, realising the second quantum revolution appears feasible, with superconducting quantum circuits having matured over the last years to the leading platform for quantum coherent information processing devices. The micro- and nanostructured circuits are formed by thin films of aluminium and are operated at temperatures of 10mK. Coherent control of the quantum states and its readout is achieved by microwave pulses generated outside the cryostats. Strong coupling to microwave photons, localized control and readout and the ability to produce purpose-built quantum circuits using established nanofabrication techniques give rise to an unprecedented variety of implementation and application schemes. For instance, scaled modern circuits have ~50 qubits and are reaching a computational complexity at the limit of today’s high-performance data centres.

In this talk an introduction to the field will be given, including a view on future technological challenges and their application potential beyond computing. I will highlight our recent work a multi-qubit -resonator system (Leppaekangas et al. PRA 2019, Yang et al. arXiv:1810.00652), show how low-frequency noise in qubits is related to material inhomogeneities (Schloer et al., PRL 2019), and discuss applications beyond computing such as quantum sensing of the amplitude and frequency of microwave fields (Kirsten et al. arxiv:1908.09556).