---
_id: '11471'
abstract:
- lang: eng
text: 'Variational quantum algorithms are promising algorithms for achieving quantum
advantage on nearterm devices. The quantum hardware is used to implement a variational
wave function and measure observables, whereas the classical computer is used
to store and update the variational parameters. The optimization landscape of
expressive variational ansätze is however dominated by large regions in parameter
space, known as barren plateaus, with vanishing gradients, which prevents efficient
optimization. In this work we propose a general algorithm to avoid barren plateaus
in the initialization and throughout the optimization. To this end we define a
notion of weak barren plateaus (WBPs) based on the entropies of local reduced
density matrices. The presence of WBPs can be efficiently quantified using recently
introduced shadow tomography of the quantum state with a classical computer. We
demonstrate that avoidance of WBPs suffices to ensure sizable gradients in the
initialization. In addition, we demonstrate that decreasing the gradient step
size, guided by the entropies allows WBPs to be avoided during the optimization
process. This paves the way for efficient barren plateau-free optimization on
near-term devices. '
acknowledgement: "We thank Marco Cerezo, Zoe Holmes, and Nicholas Hunter-Jones for
fruitful discussion and valuable feedback. We also acknowledge Adam Smith, Johannes
Jakob Meyer, and Victor V. Albert for comments on the paper. The simulations were
performed in the Julia programming\r\nlanguage [65] using the Yao module [66]. S.H.S.,
R.A.M., A.A.M. and M.S. acknowledge support by the European Research Council (ERC)
under the European Union’s Horizon 2020 research and innovation program (Grant Agreement
No. 850899)."
article_number: '020365'
article_processing_charge: No
article_type: original
author:
- first_name: Stefan
full_name: Sack, Stefan
id: dd622248-f6e0-11ea-865d-ce382a1c81a5
last_name: Sack
orcid: 0000-0001-5400-8508
- first_name: Raimel A
full_name: Medina Ramos, Raimel A
id: CE680B90-D85A-11E9-B684-C920E6697425
last_name: Medina Ramos
orcid: 0000-0002-5383-2869
- first_name: Alexios
full_name: Michailidis, Alexios
id: 36EBAD38-F248-11E8-B48F-1D18A9856A87
last_name: Michailidis
orcid: 0000-0002-8443-1064
- first_name: Richard
full_name: Kueng, Richard
last_name: Kueng
- first_name: Maksym
full_name: Serbyn, Maksym
id: 47809E7E-F248-11E8-B48F-1D18A9856A87
last_name: Serbyn
orcid: 0000-0002-2399-5827
citation:
ama: Sack S, Medina Ramos RA, Michailidis A, Kueng R, Serbyn M. Avoiding barren
plateaus using classical shadows. PRX Quantum. 2022;3(2). doi:10.1103/prxquantum.3.020365
apa: Sack, S., Medina Ramos, R. A., Michailidis, A., Kueng, R., & Serbyn, M.
(2022). Avoiding barren plateaus using classical shadows. PRX Quantum.
American Physical Society. https://doi.org/10.1103/prxquantum.3.020365
chicago: Sack, Stefan, Raimel A Medina Ramos, Alexios Michailidis, Richard Kueng,
and Maksym Serbyn. “Avoiding Barren Plateaus Using Classical Shadows.” PRX
Quantum. American Physical Society, 2022. https://doi.org/10.1103/prxquantum.3.020365.
ieee: S. Sack, R. A. Medina Ramos, A. Michailidis, R. Kueng, and M. Serbyn, “Avoiding
barren plateaus using classical shadows,” PRX Quantum, vol. 3, no. 2. American
Physical Society, 2022.
ista: Sack S, Medina Ramos RA, Michailidis A, Kueng R, Serbyn M. 2022. Avoiding
barren plateaus using classical shadows. PRX Quantum. 3(2), 020365.
mla: Sack, Stefan, et al. “Avoiding Barren Plateaus Using Classical Shadows.” PRX
Quantum, vol. 3, no. 2, 020365, American Physical Society, 2022, doi:10.1103/prxquantum.3.020365.
short: S. Sack, R.A. Medina Ramos, A. Michailidis, R. Kueng, M. Serbyn, PRX Quantum
3 (2022).
date_created: 2022-06-29T20:21:32Z
date_published: 2022-06-29T00:00:00Z
date_updated: 2023-12-13T14:47:24Z
day: '29'
ddc:
- '530'
department:
- _id: MaSe
doi: 10.1103/prxquantum.3.020365
ec_funded: 1
external_id:
arxiv:
- '2201.08194'
isi:
- '000822564300001'
file:
- access_level: open_access
checksum: a7706b28d24a0e32a55ea04b82a2df43
content_type: application/pdf
creator: dernst
date_created: 2022-06-30T07:14:48Z
date_updated: 2022-06-30T07:14:48Z
file_id: '11472'
file_name: 2022_PRXQuantum_Sack.pdf
file_size: 4231591
relation: main_file
success: 1
file_date_updated: 2022-06-30T07:14:48Z
has_accepted_license: '1'
intvolume: ' 3'
isi: 1
issue: '2'
keyword:
- General Medicine
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '06'
oa: 1
oa_version: Published Version
project:
- _id: 23841C26-32DE-11EA-91FC-C7463DDC885E
call_identifier: H2020
grant_number: '850899'
name: 'Non-Ergodic Quantum Matter: Universality, Dynamics and Control'
publication: PRX Quantum
publication_identifier:
issn:
- 2691-3399
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
related_material:
record:
- id: '14622'
relation: dissertation_contains
status: public
status: public
title: Avoiding barren plateaus using classical shadows
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 3
year: '2022'
...