1. Understanding and mitigating noise in molecular quantum linear response for spectroscopic properties on quantum computers
- Author
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Ziems, Karl Michael, Kjellgren, Erik Rosendahl, Sauer, Stephan P. A., Kongsted, Jacob, and Coriani, Sonia
- Subjects
Quantum Physics ,Physics - Chemical Physics ,Physics - Computational Physics - Abstract
The promise of quantum computing to circumvent the exponential scaling of quantum chemistry has sparked a race to develop chemistry algorithms for quantum architecture. However, most works neglect the quantum-inherent shot noise, let alone the effect of current noisy devices. Here, we present a comprehensive study of quantum linear response (qLR) theory obtaining spectroscopic properties on simulated fault-tolerant quantum computers and present-day near-term quantum hardware. This work introduces novel metrics to analyze and predict the origins of noise in the quantum algorithm, proposes an Ansatz-based error mitigation technique, and highlights the significant impact of Pauli saving in reducing measurement costs and noise. Our hardware results using up to cc-pVTZ basis set serve as proof-of-principle for obtaining absorption spectra on quantum hardware in a general approach with the accuracy of classical multi-configurational methods. Importantly, our results exemplify that substantial improvements in hardware error rates and measurement speed are necessary to lift quantum computational chemistry from proof-of-concept to an actual impact in the field.
- Published
- 2024