# Adaptive pruning-based optimization of parameterized quantum circuits

@article{Sim2020AdaptivePO, title={Adaptive pruning-based optimization of parameterized quantum circuits}, author={Sukin Sim and Jonathan Romero and J{\'e}r{\^o}me F Gonthier and Alexander A Kunitsa}, journal={Quantum Science \& Technology}, year={2020}, volume={6} }

Variational hybrid quantum–classical algorithms are powerful tools to maximize the use of noisy intermediate-scale quantum devices. While past studies have developed powerful and expressive ansatze, their near-term applications have been limited by the difficulty of optimizing in the vast parameter space. In this work, we propose a heuristic optimization strategy for such ansatze used in variational quantum algorithms, which we call ‘parameter-efficient circuit training (PECT)’. Instead of…

## 23 Citations

Noise-Robust End-to-End Quantum Control using Deep Autoregressive Policy Networks

- Computer ScienceArXiv
- 2020

This work presents a hybrid policy gradient algorithm capable of simultaneously optimizing continuous and discrete degrees of freedom in an uncertainty-resilient way, modeled by a deep autoregressive neural network to capture causality.

Quantum algorithm for credit valuation adjustments

- PhysicsNew Journal of Physics
- 2022

Quantum mechanics is well known to accelerate statistical sampling processes over classical techniques. In quantitative finance, statistical samplings arise broadly in many use cases. Here we focus…

Solving nonlinear differential equations with differentiable quantum circuits

- Computer Science
- 2020

A hybrid quantum-classical workflow where DQCs are trained to satisfy differential equations and specified boundary conditions is described, and how this approach can implement a spectral method for solving differential equations in a high-dimensional feature space is shown.

Dimensional Expressivity Analysis of Quantum Circuits

- Computer Science
- 2020

A hybrid quantum-classical approach is shown how to efficiently implement the expressivity analysis using quantum hardware, and a proof of principle demonstration of this procedure on IBM's quantum hardware is provided.

FLIP: A flexible initializer for arbitrarily-sized parametrized quantum circuits

- Computer Science
- 2021

Frederic Sauvage,1, 2 Sukin Sim,3, 4 Alexander A. Kunitsa,3 William A. Simon,3 Marta Mauri,1 and Alejandro Perdomo-Ortiz1, ∗ Zapata Computing Canada Inc., 325 Front St W, Toronto, ON, M5V 2Y1 Physics…

A quantum computing view on unitary coupled cluster theory.

- Physics, Computer ScienceChemical Society reviews
- 2022

A review of the Unitary Coupled Cluster ansatz and related ansätze which are used to variationally solve the electronic structure problem on quantum computers is presented, attempting to bring them under a common framework.

Layer VQE: A Variational Approach for Combinatorial Optimization on Noisy Quantum Computers

- Computer Science, PhysicsIEEE Transactions on Quantum Engineering
- 2022

This article presents a large-scale numerical study, simulating circuits with up to 40 qubits and 352 parameters, that demonstrates the potential of an iterative layer VQE (L-VQE) approach and shows that L-VZE is more robust to finite sampling errors and has a higher chance of finding the solution as compared with standard VZE approaches.

My title

- Computer Science
- 2022

A new algorithm called MCTS-QAOA is proposed, which combines a Monte Carlo tree search method with an improved natural policy gradient solver to optimize the discrete and continuous variables in the quantum circuit, respectively and is found to have excellent noiseresilience properties and outperforms prior algorithms in challenging instances of the generalized QAOA.

Optimisation-free Classification and Density Estimation with Quantum Circuits

- Computer Science, PhysicsArXiv
- 2022

This work demonstrates the implementation of a novel machine learning framework for classification and probability density estimation using quantum circuits and discusses a variational quantum circuit approach that could leverage quantum advantage for this framework.

Reducing the cost of energy estimation in the variational quantum eigensolver algorithm with robust amplitude estimation

- Geology
- 2022

Peter D. Johnson,1 Alexander A. Kunitsa,1 Jérôme F. Gonthier,1 Maxwell D. Radin,1 Corneliu Buda,2 Eric J. Doskocil,2 Clena M. Abuan,3 and Jhonathan Romero1 1Zapata Computing, Inc., 100 Federal St.,…

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