Javier Argüello-Luengo

Javier Argüello-Luengo

ICFO – The Institute of Photonic Sciences

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Javier Argüello-Luengo · Quantum 2020

Quantum simulation of quantum chemistry in optical lattices

"Computing the electronic structure of molecules is a central problem. Despite the enormous success of approximate methods, facing this problem exactly with conventional computers is still a tremendous challenge. This has triggered theoretical and experimental efforts to solve chemistry problems using quantum computers, with proof-of-concept results using a few qubits. An appealing alternative to this digital approach is analog quantum simulation, which relies on a highly controllable device to mimic the system of interest and gain information about the desired solution, and does not require a fully operative computer.

Here we propose how it is possible to simulate quantum chemistry problems using ultra-cold atoms as a simulator 1. In this simulator, fermionic atoms hopping in an optical potential play the role of electrons, additional optical potentials provide the nuclear attraction, and an additional atomic species mediates the electronic Coulomb repulsion. We analyze the impact of discretization and finite size effects of the lattice, and provide the working conditions required for the precise determination of the electronic energy of simple molecules. We also show how simplified models (e.g. two-dimensional 2) can lead to the first experiments in this analog simulation approach.

1 Nature 574 (7777), 215-218 (2019). 2 Phys. Rev. Research. (Accepted, 2020)."