Barren plateaus in quantum neural networks, Jarrod R. McClean, Sergio Boixo, Vadim N. Smelyanskiy, Ryan Babbush, Hartmut Neven, 2018Nature Communications, Vol. 9DOI: 10.1038/s41467-018-07090-4 - This foundational paper identifies and analyzes the barren plateau phenomenon in QNNs, explaining how gradients can vanish exponentially with the number of qubits, hindering training.
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, Patrick J. Coles, 2021Nature Reviews Physics, Vol. 3 (Springer Nature)DOI: 10.1038/s42254-021-00348-9 - This comprehensive review article covers the theoretical foundations and practical challenges of Variational Quantum Algorithms (VQAs), including optimization landscapes, barren plateaus, gradient estimation techniques, and advanced optimizers such as the Quantum Natural Gradient.
Noise-induced barren plateaus in variational quantum algorithms, Samson Wang, Enrico Fontana, M. Cerezo, Kunal Sharma, Akira Sone, Lukasz Cincio, Patrick J. Coles, 2021Nature Communications, Vol. 12 (Nature Publishing Group)DOI: 10.1038/s41467-021-27045-6 - This paper demonstrates how various noise models can induce or exacerbate barren plateaus, significantly hindering the training of variational quantum algorithms on NISQ devices.