Noise-induced barren plateaus in variational quantum algorithms

Variational Quantum Algorithms (VQAs) may be a path to quantum advantage on Noisy Intermediate-Scale Quantum (NISQ) computers. A natural question is whether noise on NISQ devices places fundamental limitations on VQA performance. We rigorously prove a serious limitation for noisy VQAs, in that the n...

Celý popis

Uloženo v:
Podrobná bibliografie
Vydáno v:Nature communications Ročník 12; číslo 1; s. 6961 - 11
Hlavní autoři: Wang, Samson, Fontana, Enrico, Cerezo, M., Sharma, Kunal, Sone, Akira, Cincio, Lukasz, Coles, Patrick J.
Médium: Journal Article
Jazyk:angličtina
Vydáno: London Nature Publishing Group UK 29.11.2021
Nature Publishing Group
Nature Portfolio
Témata:
639/766/259
639/766/483/481
Algorithms
CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
Computers
Humanities and Social Sciences
information theory and computation
multidisciplinary
Noise
Plateaus
Quantum computing
quantum information
Qubits (quantum computing)
Science
Science (multidisciplinary)
ISSN:2041-1723, 2041-1723
On-line přístup:Získat plný text
Tagy: Přidat tag
Žádné tagy, Buďte první, kdo vytvoří štítek k tomuto záznamu!
Popis
Shrnutí:Variational Quantum Algorithms (VQAs) may be a path to quantum advantage on Noisy Intermediate-Scale Quantum (NISQ) computers. A natural question is whether noise on NISQ devices places fundamental limitations on VQA performance. We rigorously prove a serious limitation for noisy VQAs, in that the noise causes the training landscape to have a barren plateau (i.e., vanishing gradient). Specifically, for the local Pauli noise considered, we prove that the gradient vanishes exponentially in the number of qubits n if the depth of the ansatz grows linearly with n . These noise-induced barren plateaus (NIBPs) are conceptually different from noise-free barren plateaus, which are linked to random parameter initialization. Our result is formulated for a generic ansatz that includes as special cases the Quantum Alternating Operator Ansatz and the Unitary Coupled Cluster Ansatz, among others. For the former, our numerical heuristics demonstrate the NIBP phenomenon for a realistic hardware noise model. Variational quantum algorithms (VQAs) are a leading candidate for useful applications of near-term quantum computing, but limitations due to unavoidable noise have not been clearly characterized. Here, the authors prove that local Pauli noise can cause vanishing gradients rendering VQAs untrainable.
Bibliografie:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
content type line 23
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
89233218CNA000001
LA-UR-20-25526
USDOE Laboratory Directed Research and Development (LDRD) Program
ISSN:2041-1723
2041-1723
DOI:10.1038/s41467-021-27045-6