Master Thesis Defense: Yangming Wang

Analog Simulation of Chemical Reactions in Superconducting Circuit

Ultrafast chemical reactions are fundamental to our understanding of the photo- and bio-chemical processes. This type of reactions includes the strong interactions between electrons and nuclei, or, a molecule and its surrounding solvents. With the breakdown of Born-Oppenheimer approximation, the complexity of classical computational methods grows exponentially up with the molecular size. This challenge stimulates our theoretical effort to devise schemes for simulating such chemical reactions on engineered analogue quantum simulators. Here, we show that the driven superconducting devices can efficiently simulate the molecular dynamics in a specific rotating frame. The demands for the number of the devices in the quantum circuit scales linearly with the simulated molecular size, as opposite to the exponetial scaling in classical simulations. We study in detail the quantum simulation of two types of chemical reactions: Marcus electron transfer and the conical intersection model. We develop a way of mapping the Hamiltonian of a driven superconducting device to the Hamiltonian of these reactions. The effectiveness of this mapping method is numerically verified. The scheme we proposed can be implemented on any near-term device with the tunable qubit-resonator coupling. Our work in this thesis is the first step towards the simulation of large-scale reactions, like protein dynamics.