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Variational quantum algorithms

Journal Article · · Nature Reviews Physics
 [1];  [1];  [2];  [3];  [4];  [5];  [2];  [6];  [7];  [1];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Quantum Science Center, Oak Ridge, TN (United States)
  2. Google Quantum AI Team, Venice, CA (United States)
  3. Univ. of Oxford (United Kingdom)
  4. NTT Corporation, Tokyo (Japan)
  5. Osaka Univ. (Japan); RIKEN, Saitama (Japan)
  6. Osaka Univ. (Japan); Japan Science and Technology Agency (JST), Saitama (Japan). PRESTO
  7. Peking Univ., Beijing (China); Stanford Univ., CA (United States)

Applications such as simulating complicated quantum systems or solving large-scale linear algebra problems are very challenging for classical computers, owing to the extremely high computational cost. Quantum computers promise a solution, although fault-tolerant quantum computers will probably not be available in the near future. Current quantum devices have serious constraints, including limited numbers of qubits and noise processes that limit circuit depth. Variational quantum algorithms (VQAs), which use a classical optimizer to train a parameterized quantum circuit, have emerged as a leading strategy to address these constraints. VQAs have now been proposed for essentially all applications that researchers have envisaged for quantum computers, and they appear to be the best hope for obtaining quantum advantage. Nevertheless, challenges remain, including the trainability, accuracy and efficiency of VQAs. Here we overview the field of VQAs, discuss strategies to overcome their challenges and finally, we highlight the exciting prospects for using them to obtain quantum advantage.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), High Energy Physics (HEP); Engineering and Physical Sciences Research Council (EPSRC); Ministry of Education, Culture, Sports, Science and Technology (MEXT); Japan Science and Technology Agency (JST); Japan Society for the Promotion of Science (JSPS); Simons Foundation; USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
Grant/Contract Number:
89233218CNA000001; AC52-06NA25396
OSTI ID:
1880487
Report Number(s):
LA-UR-20-30142
Journal Information:
Nature Reviews Physics, Journal Name: Nature Reviews Physics Journal Issue: 9 Vol. 3; ISSN 2522-5820
Publisher:
Springer NatureCopyright Statement
Country of Publication:
United States
Language:
English

References (188)

Measuring All Compatible Operators in One Series of Single-Qubit Measurements Using Unitary Transformations journal March 2020
Barren plateaus in quantum neural network training landscapes journal November 2018
Variational consistent histories as a hybrid algorithm for quantum foundations journal July 2019
Self-verifying variational quantum simulation of lattice models journal May 2019
Matchgates and classical simulation of quantum circuits journal July 2008
Variational quantum algorithms for nonlinear problems journal January 2020
Low-cost error mitigation by symmetry verification journal December 2018
Variational quantum eigensolver for frustrated quantum systems journal August 2020
Quantum Algorithm for Linear Systems of Equations journal October 2009
Quantum Algorithms for Systems of Linear Equations Inspired by Adiabatic Quantum Computing journal February 2019
Variational Spin-Squeezing Algorithms on Programmable Quantum Sensors journal December 2019
Accelerating Lattice Quantum Field Theory Calculations via Interpolator Optimization Using Noisy Intermediate-Scale Quantum Computing journal February 2020
Multivariate stochastic approximation using a simultaneous perturbation gradient approximation journal March 1992
Simulated Quantum Computation of Molecular Energies journal September 2005
Quantum Circuits That Can Be Simulated Classically in Polynomial Time journal January 2002
The Density Matrix Renormalization Group in Quantum Chemistry journal May 2011
Error mitigation for short-depth quantum circuits text January 2016
Hardware-efficient Variational Quantum Eigensolver for Small Molecules and Quantum Magnets text January 2017
Quantum Simulation of Electronic Structure with Linear Depth and Connectivity text January 2017
A quantum algorithm to train neural networks using low-depth circuits preprint January 2017
Learning the quantum algorithm for state overlap text January 2018
Circuit-centric quantum classifiers text January 2018
Variational Quantum Computation of Excited States text January 2018
Methodology for replacing indirect measurements with direct measurements text January 2019
Quantum Computation of Electronic Transitions using a Variational Quantum Eigensolver text January 2019
Variational Quantum Fidelity Estimation text January 2019
An Adaptive Optimizer for Measurement-Frugal Variational Algorithms text January 2019
Non-unitary operations for ground-state calculations in near term quantum computers text January 2019
Quantum Orbital-Optimized Unitary Coupled Cluster Methods in the Strongly Correlated Regime: Can Quantum Algorithms Outperform their Classical Equivalents? text January 2019
Quantum neural network preprint January 2001
Classical simulation of noninteracting-fermion quantum circuits text January 2001
New perspectives on unitary coupled-cluster theory journal January 2006
Expressibility and Entangling Capability of Parameterized Quantum Circuits for Hybrid Quantum‐Classical Algorithms journal October 2019
Variational Quantum Generators: Generative Adversarial Quantum Machine Learning for Continuous Distributions journal December 2020
Fermionic Quantum Computation journal May 2002
Variational Quantum Factoring book January 2019
Random Quantum Circuits are Approximate 2-designs journal July 2009
Local Random Quantum Circuits are Approximate Polynomial-Designs journal August 2016
Concrete resource analysis of the quantum linear-system algorithm used to compute the electromagnetic scattering cross section of a 2D target journal January 2017
On the universality of the quantum approximate optimization algorithm journal August 2020
Layerwise learning for quantum neural networks journal January 2021
Asymptotic expansion approximation for spatial structure arising from directionally biased movement journal March 2020
Quantum Computation and Quantum Information book January 2011
Quantum Information Theory book May 2013
Generalized Unitary Coupled Cluster Wave functions for Quantum Computation journal November 2018
Unitary Partitioning Approach to the Measurement Problem in the Variational Quantum Eigensolver Method journal November 2019
Jastrow-type Decomposition in Quantum Chemistry for Low-Depth Quantum Circuits journal January 2020
A Multireference Quantum Krylov Algorithm for Strongly Correlated Electrons journal February 2020
Quantum machine learning journal September 2017
Hardware-efficient variational quantum eigensolver for small molecules and quantum magnets journal September 2017
A variational eigenvalue solver on a photonic quantum processor journal July 2014
Quantum Darwinism journal March 2009
Quantum principal component analysis journal July 2014
An adaptive variational algorithm for exact molecular simulations on a quantum computer journal July 2019
Decoding quantum errors with subspace expansions journal January 2020
Training deep quantum neural networks journal February 2020
Cost function dependent barren plateaus in shallow parametrized quantum circuits journal March 2021
Quantum generalisation of feedforward neural networks journal September 2017
Enhancing quantum control by bootstrapping a quantum processor of 12 qubits journal October 2017
A generative modeling approach for benchmarking and training shallow quantum circuits journal May 2019
Variational quantum state diagonalization journal June 2019
Variational ansatz-based quantum simulation of imaginary time evolution journal September 2019
Efficient symmetry-preserving state preparation circuits for the variational quantum eigensolver algorithm journal January 2020
The Born supremacy: quantum advantage and training of an Ising Born machine journal July 2020
Variational fast forwarding for quantum simulation beyond the coherence time journal September 2020
Efficient and noise resilient measurements for quantum chemistry on near-term quantum computers journal February 2021
Multi-exponential error extrapolation and combining error mitigation techniques for NISQ applications journal May 2021
Parallel quantum simulation of large systems on small NISQ computers journal May 2021
Quantum convolutional neural networks journal August 2019
Variational quantum unsampling on a quantum photonic processor journal January 2020
Predicting many properties of a quantum system from very few measurements journal June 2020
Supervised learning with quantum-enhanced feature spaces journal March 2019
Error mitigation extends the computational reach of a noisy quantum processor journal March 2019
Quantum supremacy using a programmable superconducting processor journal October 2019
The power of quantum neural networks journal June 2021
Measurement optimization in the variational quantum eigensolver using a minimum clique cover journal March 2020
Quantum orbital-optimized unitary coupled cluster methods in the strongly correlated regime: Can quantum algorithms outperform their classical equivalents? journal March 2020
A variational solution of the time-dependent Schrodinger equation journal January 1964
Black holes as mirrors: quantum information in random subsystems journal September 2007
The theory of variational hybrid quantum-classical algorithms journal February 2016
Application of fermionic marginal constraints to hybrid quantum algorithms journal May 2018
Learning the quantum algorithm for state overlap journal November 2018
Noise resilience of variational quantum compiling journal April 2020
A non-orthogonal variational quantum eigensolver journal July 2020
Variational-state quantum metrology journal August 2020
On barren plateaus and cost function locality in variational quantum algorithms journal May 2021
Quantum autoencoders for efficient compression of quantum data journal August 2017
Quantum optimization using variational algorithms on near-term quantum devices journal June 2018
Strategies for quantum computing molecular energies using the unitary coupled cluster ansatz journal October 2018
Large gradients via correlation in random parameterized quantum circuits journal January 2021
Characterizing the loss landscape of variational quantum circuits journal February 2021
Higher order derivatives of quantum neural networks with barren plateaus journal June 2021
Solving quantum statistical mechanics with variational autoregressive networks and quantum circuits journal February 2021
Characterizing local noise in QAOA circuits journal August 2020
Minimizing Estimation Runtime on Noisy Quantum Computers journal March 2021
Qubit-ADAPT-VQE: An Adaptive Algorithm for Constructing Hardware-Efficient Ansätze on a Quantum Processor journal April 2021
Correlation-Informed Permutation of Qubits for Reducing Ansatz Depth in the Variational Quantum Eigensolver journal June 2021
Measurement Cost of Metric-Aware Variational Quantum Algorithms journal August 2021
Learning-Based Quantum Error Mitigation journal November 2021
Connecting Ansatz Expressibility to Gradient Magnitudes and Barren Plateaus journal January 2022
Product spectrum ansatz and the simplicity of thermal states journal September 2019
Variational quantum algorithms for nonlinear problems journal January 2020
X Y mixers: Analytical and numerical results for the quantum alternating operator ansatz journal January 2020
Circuit-centric quantum classifiers journal March 2020
Quantum singular value decomposer journal June 2020
Measurement reduction in variational quantum algorithms journal June 2020
Noise-resilient variational hybrid quantum-classical optimization journal November 2020
Estimating the gradient and higher-order derivatives on quantum hardware journal January 2021
Effect of data encoding on the expressive power of variational quantum-machine-learning models journal March 2021
Abrupt transitions in variational quantum circuit training journal March 2021
Mitigating measurement errors in multiqubit experiments journal April 2021
Solving nonlinear differential equations with differentiable quantum circuits journal May 2021
Universal variational quantum computation journal March 2021
Classical simulation of noninteracting-fermion quantum circuits journal March 2002
Progress towards practical quantum variational algorithms journal October 2015
Training a quantum optimizer journal August 2016
Hybrid quantum-classical hierarchy for mitigation of decoherence and determination of excited states journal April 2017
Quantum approximate optimization algorithm for MaxCut: A fermionic view journal February 2018
Quantum circuit learning journal September 2018
Differentiable learning of quantum circuit Born machines journal December 2018
Low-cost error mitigation by symmetry verification journal December 2018
Mitigating algorithmic errors in a Hamiltonian simulation journal January 2019
Recovering noise-free quantum observables journal January 2019
Evaluating analytic gradients on quantum hardware journal March 2019
Variational quantum algorithms for discovering Hamiltonian spectra journal June 2019
Resource Estimation for Quantum Variational Simulations of the Hubbard Model journal July 2020
Mitigating Realistic Noise in Practical Noisy Intermediate-Scale Quantum Devices journal March 2021
Variational Circuit Compiler for Quantum Error Correction journal March 2021
Noise-Assisted Quantum Autoencoder journal May 2021
Variational quantum eigensolver for frustrated quantum systems journal August 2020
Strategies for solving the Fermi-Hubbard model on near-term quantum computers journal December 2020
Quantum Algorithm for Linear Systems of Equations journal October 2009
Hybrid Quantum-Classical Approach to Quantum Optimal Control journal April 2017
Error Mitigation for Short-Depth Quantum Circuits journal November 2017
Quantum Simulation of Electronic Structure with Linear Depth and Connectivity journal March 2018
Quantum Machine Learning in Feature Hilbert Spaces journal February 2019
Experimental Realization of a Quantum Autoencoder: The Compression of Qutrits via Machine Learning journal February 2019
Quantum Algorithms for Systems of Linear Equations Inspired by Adiabatic Quantum Computing journal February 2019
Accelerated Variational Quantum Eigensolver journal April 2019
Error-Mitigated Digital Quantum Simulation journal May 2019
Quantum Computation of Electronic Transitions Using a Variational Quantum Eigensolver journal June 2019
Nonunitary Operations for Ground-State Calculations in Near-Term Quantum Computers journal September 2019
Variational Spin-Squeezing Algorithms on Programmable Quantum Sensors journal December 2019
Variational Quantum Simulation of General Processes journal June 2020
Low-Depth Gradient Measurements Can Improve Convergence in Variational Hybrid Quantum-Classical Algorithms journal April 2021
Barren Plateaus Preclude Learning Scramblers journal May 2021
Training Variational Quantum Algorithms Is NP-Hard journal September 2021
Quantum Algorithm Providing Exponential Speed Increase for Finding Eigenvalues and Eigenvectors journal December 1999
Quantum Fingerprinting journal September 2001
Methodology for replacing indirect measurements with direct measurements journal August 2019
Variational quantum eigensolver with fewer qubits journal September 2019
Superfast encodings for fermionic quantum simulation journal October 2019
Subspace-search variational quantum eigensolver for excited states journal October 2019
Precise measurement of quantum observables with neural-network estimators journal June 2020
Expressive power of parametrized quantum circuits journal July 2020
Orbital optimized unitary coupled cluster theory for quantum computer journal September 2020
Sequential minimal optimization for quantum-classical hybrid algorithms journal October 2020
Variational quantum algorithm for nonequilibrium steady states journal November 2020
Quantum-optimal-control-inspired ansatz for variational quantum algorithms journal May 2021
Exponential Error Suppression for Near-Term Quantum Devices journal September 2021
Multistart Methods for Quantum Approximate optimization conference September 2019
$O(N^3)$ Measurement Cost for Variational Quantum Eigensolver on Molecular Hamiltonians journal January 2020
Universal Quantum Simulators journal August 1996
Quantum computational advantage using photons journal December 2020
Simulating Quantum Computation by Contracting Tensor Networks journal January 2008
Quantum Algorithm for Systems of Linear Equations with Exponentially Improved Dependence on Precision journal January 2017
Quantum Circuits That Can Be Simulated Classically in Polynomial Time journal January 2002
Efficient variational simulation of non-trivial quantum states journal January 2019
Quantum Computing in the NISQ era and beyond journal August 2018
Quantum-assisted quantum compiling journal May 2019
Variational Quantum Computation of Excited States journal July 2019
Theory of variational quantum simulation journal October 2019
An initialization strategy for addressing barren plateaus in parametrized quantum circuits journal December 2019
Data re-uploading for a universal quantum classifier journal February 2020
Variational Quantum Fidelity Estimation journal March 2020
An Adaptive Optimizer for Measurement-Frugal Variational Algorithms journal May 2020
Quantum Natural Gradient journal May 2020
Scaling of variational quantum circuit depth for condensed matter systems journal May 2020
Stochastic gradient descent for hybrid quantum-classical optimization journal August 2020
Yao.jl: Extensible, Efficient Framework for Quantum Algorithm Design journal October 2020
Efficient quantum measurement of Pauli operators in the presence of finite sampling error journal January 2021
Expressibility of the alternating layered ansatz for quantum computation journal April 2021
Error mitigation on a near-term quantum photonic device journal May 2021
Effect of barren plateaus on gradient-free optimization journal October 2021
Error mitigation with Clifford quantum-circuit data journal November 2021
From the Quantum Approximate Optimization Algorithm to a Quantum Alternating Operator Ansatz journal February 2019
Quantum Simulation with Hybrid Tensor Networks audiovisual January 2020
Hybrid Quantum-Classical Algorithms and Quantum Error Mitigation journal March 2021

Cited By (9)

Freedom of the mixer rotation axis improves performance in the quantum approximate optimization algorithm journal December 2021
Quantum Variational Optimization of Ramsey Interferometry and Atomic Clocks journal December 2021
Modeling and mitigation of cross-talk effects in readout noise with applications to the Quantum Approximate Optimization Algorithm journal June 2021
Addition and Differentiation of ZX-Diagrams text January 2022
An Optimal Oracle Separation of Classical and Quantum Hybrid Schemes text January 2022
Learning temporal data with variational quantum recurrent neural network text January 2020
An efficient quantum algorithm for the time evolution of parameterized circuits text January 2021
Improved accuracy on noisy devices by non-unitary Variational Quantum Eigensolver for chemistry applications preprint January 2021
Addition and Differentiation of ZX-diagrams preprint January 2022

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