eprintid: 10126773
rev_number: 12
eprint_status: archive
userid: 608
dir: disk0/10/12/67/73
datestamp: 2021-08-02 16:18:04
lastmod: 2021-08-02 16:18:04
status_changed: 2021-08-02 16:18:04
type: article
metadata_visibility: show
creators_name: Grant, E
creators_name: Wossnig, L
creators_name: Ostaszewski, M
creators_name: Benedetti, M
title: An initialization strategy for addressing barren plateaus in parametrized quantum circuits
ispublished: pub
divisions: UCL
divisions: A01
divisions: B04
divisions: C05
keywords: Quantum Neural Networks, Variational Quantum Eigensolvers, Quantum Machine Learning
note: © 2019. This Paper is published in Quantum under the Creative Commons Attribution 4.0 International (CC BY 4.0) license (https://creativecommons.org/licenses/by/4.0/).
abstract: Parametrized quantum circuits initialized with random initial parameter values are characterized by barren plateaus where the gradient becomes exponentially small in the number of qubits. In this technical note we theoretically motivate and empirically validate an initialization strategy which can resolve the barren plateau problem for practical applications. The technique involves randomly selecting some of the initial parameter values, then choosing the remaining values so that the circuit is a sequence of shallow blocks that each evaluates to the identity. This initialization limits the effective depth of the circuits used to calculate the first parameter update so that they cannot be stuck in a barren plateau at the start of training. In turn, this makes some of the most compact ans\"atze usable in practice, which was not possible before even for rather basic problems. We show empirically that variational quantum eigensolvers and quantum neural networks initialized using this strategy can be trained using a gradient based method.
date: 2019
official_url: http://dx.doi.org/10.22331/q-2019-12-09-214
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1722734
doi: 10.22331/q-2019-12-09-214
lyricists_name: Benedetti, Marcello
lyricists_id: MBENE91
actors_name: Zahnhausen-Stuber, Petra
actors_id: PMZAH20
actors_role: owner
full_text_status: public
publication: Quantum
volume: 3
article_number: 214
citation:        Grant, E;    Wossnig, L;    Ostaszewski, M;    Benedetti, M;      (2019)    An initialization strategy for addressing barren plateaus in parametrized quantum circuits.                   Quantum , 3     , Article 214.  10.22331/q-2019-12-09-214 <https://doi.org/10.22331/q-2019-12-09-214>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10126773/1/q-2019-12-09-214.pdf