Core Concepts
Chemically relevant dynamical processes can be efficiently simulated on a quantum computer by preparing initial states through a hierarchical scattering process and then measuring dynamical quantities of interest.
Abstract
The content discusses a computational framework for efficiently simulating chemically relevant dynamical processes on a quantum computer. The key ideas are:
Preparing initial states: The framework starts by efficiently preparing the ground states of atoms, which can be done with constant overhead. These atomic states are then combined through a hierarchical scattering process, using artificial potentials and photonic fields to boost the success probability of forming desired molecular states. This avoids the need to prepare the generally hard-to-obtain molecular ground states.
Simulating dynamics: The prepared molecular states are then evolved using efficient quantum simulation of the relevant Hamiltonians, which are 2-local due to the nature of the Coulomb interaction. This allows for polynomial-sized quantum circuits.
Measuring observables: A wide range of dynamical quantities of chemical interest can be measured, such as reaction rates, spectroscopic observables, and free energies. The framework leverages techniques like weak measurements and history state encoding to efficiently extract these observables from the quantum dynamics.
The content argues that this approach can address a broad class of chemically relevant problems that are efficiently solvable on a quantum computer, in contrast to the generally hard problem of finding molecular ground states. Exemplary applications are discussed, including photochemistry, spectroscopy, and free energy simulations.