Exploring pathways towards quantum advantage in quantum chemistry: the case of a molecule with half-M\"obius topology

TL;DR

This paper demonstrates the use of superconducting quantum processors with advanced algorithms to simulate complex molecules with half-M"obius topology, showing progress towards practical quantum advantage in quantum chemistry.

Contribution

It introduces the application of SqDRIFT, a quantum diagonalization algorithm, to larger active spaces in quantum chemistry simulations on superconducting quantum processors.

Findings

Reliable simulations on 36 orbitals (72 qubits) achieved.

Extended studies up to 50 orbitals (100 qubits).

Systematic increase in active space improves accuracy.

Abstract

We report quantum chemistry calculations performed on superconducting quantum processors for a molecule exhibiting the half-M\"obius electronic topology originally introduced by Ron\v{c}evi\'c et al. Using SqDRIFT, a randomized sample-based Krylov quantum diagonalization algorithm, we achieve reliable quantum simulations on active spaces corresponding to 36 orbitals (72 qubits) and extend previous studies up to 50 orbitals (100 qubits). We demonstrate that a systematic increase of active space sizes, which has a concrete impact on the accuracy of the electronic structure description, is achievable with state-of-the-art quantum processors, thus offering a promising path towards practically relevant quantum-assisted electronic-structure calculations.