Machine learning can be substantially powered by a quantum computer owing to its huge Hilbert space and inherent quantum parallelism. In the pursuit of quantum advantages for machine learning with noisy intermediate-scale quantum devices, it was proposed that the learning model can be designed in an end-to-end fashion, i.e., the quantum ansatz is parameterized by directly manipulable control pulses without circuit design and compilation. Such gate-free models are hardware friendly and can fully exploit limited quantum resources. Here, we report the first experimental realization of quantum end-to-end machine learning on a superconducting processor. The trained model can achieve 98% recognition accuracy for two handwritten digits (via two qubits) and 89% for four digits (via three qubits) in the MNIST (Mixed National Institute of Standards and Technology) database. The experimental results exhibit the great potential of quantum end-to-end learning for resolving complex real-world tasks when more qubits are available.
@article{arxiv.2203.09080,
title = {Experimental Quantum End-to-End Learning on a Superconducting Processor},
author = {Xiaoxuan Pan and Xi Cao and Weiting Wang and Ziyue Hua and Weizhou Cai and Xuegang Li and Haiyan Wang and Jiaqi Hu and Yipu Song and Dong-Ling Deng and Chang-Ling Zou and Re-Bing Wu and Luyan Sun},
journal= {arXiv preprint arXiv:2203.09080},
year = {2022}
}