Mechanical, Maritime, and Materials Engineering (3mE) seminar by prof. Jason Twamley (Okinawa Institute for Science and Technology) on "Engineered Quantum Machines - mechanics and spin control".

Abstract: The quest to build larger and more massive quantum machines probes regimes of quantum mechanics never explored previously. Quantum systems with large mass permits one to explore the interaction of quantum with gravity, the use of such sensitive fragile systems as precision acceleration and inertial sensors, and potential long lived components in quantum information technologies. Researchers have developed many techniques towards the trapping and cooling of nano-micron scaled objects but in this talk I will discuss the advantages of magnetic trapping. Magnetic trapping can be achieved completely passively without the need for high power lasers used in optical trapping, or the rapidly oscillating electromagnetic fields used in Paul traps. This complete passive type of trap heralds the potential for very low noise levitation and the creation of ultra-high-motional-Q massive oscillators. Such oscillators may be put into motion superposition states via many techniques and have the potential to be the largest Schrodinger Cats created to date. In this talk I will describe some recent theoretical and experimental works related to this topic including experiments to produce high-Q magnetically levitated mechanical resonators, theoretical proposals for the production of massive macroscopic quantum superpositions, ideas to spin up levitated magnonic crystals to ultra-high rotational speeds, and details of a new error mitigation technique which can protect qubits from non-Markovian noise, extending the coherence time of an ensemble of spins by several orders of magnitude. This latter discovery can be of use for many different types of quantum information processing tasks.