English

Avoiding barren plateaus in the variational determination of geometric entanglement

Quantum Physics 2023-04-27 v1

Abstract

The barren plateau phenomenon is one of the main obstacles to implementing variational quantum algorithms in the current generation of quantum processors. Here, we introduce a method capable of avoiding the barren plateau phenomenon in the variational determination of the geometric measure of entanglement for a large number of qubits. The method is based on measuring compatible two-qubit local functions whose optimization allows for achieving a well-suited initial condition, from which a global function can be further optimized without encountering a barren plateau. We analytically demonstrate that the local functions can be efficiently estimated and optimized. Numerical simulations up to 18-qubit GHZ and W states demonstrate that the method converges to the exact value. In particular, the method allows for escaping from barren plateaus induced by hardware noise or global functions defined on high-dimensional systems. Numerical simulations with noise are in agreement with experiments carried out on IBM's quantum processors for 7 qubits.

Keywords

Cite

@article{arxiv.2304.13388,
  title  = {Avoiding barren plateaus in the variational determination of geometric entanglement},
  author = {Leonardo Zambrano and Andrés Damián Muñoz-Moller and Mario Muñoz and Luciano Pereira and Aldo Delgado},
  journal= {arXiv preprint arXiv:2304.13388},
  year   = {2023}
}