Analogue simulations and digital processing with spins in quantum dots

• Speaker: Dehollain, Juan Pablo (U of Tech. Sydney, Australia)

Electrostatically defined quantum dots in semiconductors are one of the leading platforms for the development of quantum technologies, owing to their fast and efficient control and measurement, as well as their compatibility of fabrication with commercial semiconductor industry processes. At the Vandersypen Lab, we focus on using the spin and charge degrees of freedom of electrons confined in quantum dots, to explore physics through analogue quantum simulations and digital quantum information processing.

In this talk I will delve into some of our latest and most exciting experiments. I will begin with a description of the types of quantum dot arrays that we operate, highlighting the techniques that we have developed recently to overcome the problem of disorder and efficient control, which is crucial to the operation and scale-up of these systems as quantum simulators and processors. I will then describe our latest quantum simulator device—a 2x2 plaquette of quantum dots in a GaAs heterostructure—which we use to demonstrate Nagaoka ferromagnetism, one of the well-known theories of ferromagnetism based on the Hubbard model, which had yet to be demonstrated experimentally. Finally, I will present the capabilities of our silicon-based 2-qubit quantum information processor, with an outlook on how this technology can be further developed towards a large-scale universal quantum computer.