Speaker: Dr. Sauro SUCCI
Title: Whither quantum computing for fluids?
Abstract: In the last decade quantum computing has attracted enormous interest both at academic and industrial level, mainly in connection with its tantalising potential for solving (some) problems beyond reach for any foreseeable classical computer. Even though the mainstream of quantum computing is focussed on quantum physics, engineering and information dynamics, increasing attention has recently been directed towards the exploration of the potential of quantum computing for classical physics, most notably fluid dynamics and other nonlinear transport phenomena. The potential of quantum computing for fluids is staggering; in a blue-sky scenario a quantum computer with slightly above hundred logical qubits could perform global weather forecast simulations at sub-meter resolution. However, solving fluid dynamics on quantum computers is a steep challenge on top of a challenge because, besides the notorious hurdles of decoherence and loss of entanglement, the physics of fluids, being generally nonlinear and dissipative, cannot be mapped directly onto the unitary gates of quantum computers. Hence, non trivial extra-steps need to be taken in order to formulate an algorithm describing nonlinear and dissipative physics within a linear and unitary mathematical harness. After a brief introduction to the quantum simulation of fluids, in this talk we shall focus on a specific technique, known as Carleman embedding, which trades nonlinearity for infinite dimensionality. This technique has shown very encouraging results on classical computers but the formulation of a corresponding quantum algorithm still faces a number of major challenges, which we shall discuss and comment upon. Finally, it is argued that the search of quantum algorithms for fluids bears a major foundational value, regardless of its success in achieving quantum advantage over classical computational fluid dynamics, as it may shed new light on the emergence of classical physics from the underlying quantum world.
