• DOI:10.1103/PhysRevResearch.4.033154
• Corpus ID: 251871923

Measurements as a roadblock to near-term practical quantum advantage in chemistry: Resource analysis

@article{Gonthier2020MeasurementsAA,
  title={Measurements as a roadblock to near-term practical quantum advantage in chemistry: Resource analysis},
  author={J{\'e}r{\^o}me F Gonthier and Maxwell D. Radin and Corneliu Buda and Eric Doskocil and Clena M. Abuan and Jhonathan Romero},
  journal={Physical Review Research},
  year={2020}
}

• Jérôme F Gonthier, M. Radin, +3 authors J. Romero
• Published 7 December 2020
• Physics
• Physical Review Research

Recent advances in quantum computing devices have brought attention to hybrid quantum-classical algorithms like the Variational Quantum Eigensolver (VQE) as a potential route to practical quantum advantage in chemistry. However, it is not yet clear whether such algorithms, even in the absence of device error, could actually achieve quantum advantage for systems of practical interest. We have performed an exhaustive analysis to estimate the number of qubits and number of measurements required to compute the combustion energies of small organic molecules and related systems to within chemical accuracy of experimental values using VQE. We consider several key modern improvements to VQE, including low-rank factorizations of the Hamiltonian. Our results indicate that although these techniques are useful, they will not be sufficient to achieve practical quantum computational advantage for our molecular set, or for similar molecules. This suggests that novel approaches to operator estimation leveraging quantum coherence, such as Enhanced Likelihood Functions, may be required.