Published April 2025 | Version Published
Journal Article

Barren plateaus in variational quantum computing

  • 1. ROR icon Los Alamos National Laboratory
  • 2. ROR icon École Polytechnique Fédérale de Lausanne
  • 3. ROR icon Chulalongkorn University
  • 4. ROR icon California Institute of Technology
  • 5. ROR icon IBM Research - Thomas J. Watson Research Center
  • 6. Tensor Institute, Montreal, Quebec, Canada
  • 7. ROR icon University of Quebec at Montreal
  • 8. Normal Computing Corporation, New York, NY, USA
  • 9. ROR icon Google (United States)

Abstract

Variational quantum computing offers a flexible computational approach with a broad range of applications. However, a key obstacle to realizing their potential is the barren plateau (BP) phenomenon. When a model exhibits a BP, its parameter optimization landscape becomes exponentially flat and featureless as the problem size increases. Importantly, all the moving pieces of an algorithm — choices of ansatz, initial state, observable, loss function and hardware noise — can lead to BPs if they are ill-suited. As BPs strongly impact on trainability, researchers have dedicated considerable effort to develop theoretical and heuristic methods to understand and mitigate their effects. As a result, the study of BPs has become a thriving area of research, influencing and exchanging ideas with other fields such as quantum optimal control, tensor networks and learning theory. This article provides a review of the current understanding of the BP phenomenon.

Copyright and License

© 2025 Springer Nature Limited.

Acknowledgement

The authors thank M. Kieferova, P. Bermejo and T. O’Leary for their feedback on our manuscript. M.L. was supported by the Center for Nonlinear Studies at Los Alamos National Laboratory (LANL). M.L. acknowledges support by the Laboratory Directed Research and Development (LDRD) program of LANL under project number 20230049DR. S.T. and Z.H. acknowledge support from the Sandoz Family Foundation-Monique de Meuron program for Academic Promotion. This research was partly supported (L.C.) by the Quantum Science Center, a National Quantum Science Initiative of the Department of Energy, managed by Oak Ridge National Laboratory. L.C. was also supported by the US Department of Energy, Office of Science, Office of Advanced Scientific Computing Research, under Computational Partnerships program. M.C. acknowledges support by the LANL ASC Beyond Moore’s Law project and by LDRD program of LANL under project number 20230527ECR.

Additional details

Additional titles

Alternative title
A Review of Barren Plateaus in Variational Quantum Computing

Related works

Describes
Journal Article: https://rdcu.be/eyKP2 (URL)
Is new version of
Discussion Paper: arXiv:2405.00781 (arXiv)

Funding

Los Alamos National Laboratory
20230049DR
Quantum Science Center
United States Department of Energy
Los Alamos National Laboratory
20230527ECR

Dates

Accepted
2025-02-10
Available
2025-03-26
Published online

Caltech Custom Metadata

Caltech groups
Institute for Quantum Information and Matter, Division of Physics, Mathematics and Astronomy (PMA)
Publication Status
Published