Latency considerations for stochastic optimizers in variational quantum algorithms

Abstract

Variational quantum algorithms, which have risen to prominence in the noisy intermediate-scale quantum setting, require the implementation of a stochastic optimizer on classical hardware. To date, most research has employed algorithms based on the stochastic gradient iteration as the stochastic classical optimizer. In this work we propose instead using stochastic optimization algorithms that yield stochastic processes emulating the dynamics of classical deterministic algorithms. This approach results in methods with theoretically superior worst-case iteration complexities, at the expense of greater per-iteration sample (shot) complexities. We investigate this trade-off both theoretically and empirically and conclude that preferences for a choice of stochastic optimizer should explicitly depend on a function of both latency and shot execution times.

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Cited by in corpus (5)

• Guaranteed efficient energy estimation of quantum many-body Hamiltonians using ShadowGrouping
• Multi-variable integration with a variational quantum circuit
• A Novel Noise-Aware Classical Optimizer for Variational Quantum Algorithms
• End-to-End Protocol for High-Quality QAOA Parameters with Few Shots
• A Noise-Aware Scalable Subspace Classical Optimizer for the Quantum Approximate Optimization Algorithm