Simulating Chemistry with Fermionic Optical Superlattices

TL;DR

This paper demonstrates how variational quantum chemistry methods can be mapped onto ultracold fermionic atoms in optical superlattices, enabling molecular energy measurements with current quantum simulation techniques.

Contribution

It introduces a novel mapping of quantum chemistry Ansätze to ultracold fermion systems, facilitating experimental simulation without complex operations like shuttling or long-range interactions.

Findings

Mapping of quantum chemistry to optical superlattices established

Complete compilation pipeline from Hamiltonian to lattice operations provided

Quantum resource estimates for small experiments detailed

Abstract

We show that quantum number preserving Ans\"{a}tze for variational optimization in quantum chemistry find an elegant mapping to ultracold fermions in optical superlattices. Using native Hubbard dynamics, trial ground states of molecular Hamiltonians can be prepared and their molecular energies measured in the lattice. The scheme requires local control over interactions and chemical potentials and global control over tunneling dynamics, but foregoes the need for optical tweezers, shuttling operations, or long-range interactions. We describe a complete compilation pipeline from the molecular Hamiltonian to the sequence of lattice operations, thus providing a concrete link between quantum simulation and chemistry. Our work enables the application of recent quantum algorithmic techniques, such as Double Factorization and quantum Tailored Coupled Cluster, to present-day fermionic optical lattice systems with significant improvements in the required number of experimental repetitions. We provide detailed quantum resource estimates for small non-trivial hardware experiments.