Role of coherence in many-body Quantum Reservoir Computing

TL;DR

This paper investigates how quantum coherence and correlations influence the performance of many-body quantum reservoir computing, highlighting the importance of quantum effects in processing temporal information.

Contribution

It establishes a link between quantum coherence and reservoir performance, analyzing the impact of quantum effects in a many-body system for temporal tasks.

Findings

Quantum coherence correlates with improved performance.

Quantum effects are crucial in the ergodic regime.

Finite measurement resources and noise limit quantum advantage.

Abstract

Quantum Reservoir Computing (QRC) offers potential advantages over classical reservoir computing, including inherent processing of quantum inputs and a vast Hilbert space for state exploration. Yet, the relation between the performance of reservoirs based on complex and many-body quantum systems and non-classical state features is not established. Through an extensive analysis of QRC based on a transverse-field Ising model we show how different quantum effects, such as quantum coherence and correlations, contribute to improving the performance in temporal tasks, as measured by the Information Processing Capacity. Additionally, we critically assess the impact of finite measurement resources and noise on the reservoir's dynamics in different regimes, quantifying the limited ability to exploit quantum effects for increasing damping and noise strengths. Our results reveal a monotonic relationship between reservoir performance and coherence, along with the importance of quantum effects in the ergodic regime.