Entropy (Nov 2024)

Quantum Circuit Architecture Search on a Superconducting Processor

  • Kehuan Linghu,
  • Yang Qian,
  • Ruixia Wang,
  • Meng-Jun Hu,
  • Zhiyuan Li,
  • Xuegang Li,
  • Huikai Xu,
  • Jingning Zhang,
  • Teng Ma,
  • Peng Zhao,
  • Dong E. Liu,
  • Min-Hsiu Hsieh,
  • Xingyao Wu,
  • Yuxuan Du,
  • Dacheng Tao,
  • Yirong Jin,
  • Haifeng Yu

DOI
https://doi.org/10.3390/e26121025
Journal volume & issue
Vol. 26, no. 12
p. 1025

Abstract

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Variational quantum algorithms (VQAs) have shown strong evidence to gain provable computational advantages in diverse fields such as finance, machine learning, and chemistry. However, the heuristic ansatz exploited in modern VQAs is incapable of balancing the trade-off between expressivity and trainability, which may lead to degraded performance when executed on noisy intermediate-scale quantum (NISQ) machines. To address this issue, here, we demonstrate the first proof-of-principle experiment of applying an efficient automatic ansatz design technique, i.e., quantum architecture search (QAS), to enhance VQAs on an 8-qubit superconducting quantum processor. In particular, we apply QAS to tailor the hardware-efficient ansatz toward classification tasks. Compared with heuristic ansätze, the ansatz designed by QAS improves the test accuracy from 31% to 98%. We further explain this superior performance by visualizing the loss landscape and analyzing effective parameters of all ansätze. Our work provides concrete guidance for developing variable ansätze to tackle various large-scale quantum learning problems with advantages.

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