A variational eigenvalue solver on a photonic quantum processor, Alberto Peruzzo, Jarrod McClean, Peter Shadbolt, Man-Hong Yung, Xiao-Qi Zhou, Peter J. Love, Alán Aspuru-Guzik, and Jeremy L. O'Brien, 2014Nature Communications, Vol. 5DOI: 10.1038/ncomms5213 - The pioneering paper that introduced the Variational Quantum Eigensolver (VQE), demonstrating the hybrid quantum-classical approach for quantum chemistry calculations.
Variational Quantum Algorithms, M. Cerezo, Andrew Arrasmith, Ryan Babbush, Simon C. Benjamin, Suguru Endo, Keisuke Fujii, Jarrod R. McClean, Kosuke Mitarai, Xiao Yuan, Lukasz Cincio, and Patrick J. Coles, 2021Nature Reviews Physics, Vol. 3 (Nature Portfolio)DOI: 10.1038/s42254-021-00348-9 - A comprehensive review providing an up-to-date overview of VQAs, including their theory, applications, and challenges.