Quantum Autoencoder for Multivariate Time Series Anomaly Detection

--Anomaly Detection (AD) defines the task of identifying observations or events that deviate from typical - or normal - patterns, a critical capability in IT security for recognizing incidents such as system misconfigurations, malware infections, or cyberattacks. In enterprise environments like SAP HANA Cloud systems, this task often involves monitoring high-dimensional, multivariate time series (MTS) derived from telemetry and log data. One approach is the Quantum Autoencoder (QAE), an emerging and promising method with potential for application in both data compression and AD. However, prior applications of QAEs to time series AD have been restricted to univariate data, limiting their relevance for real-world enterprise systems. In this work, we introduce a novel QAE-based framework designed specifically for MTS AD towards enterprise scale. We theoretically develop and experimentally validate the architecture, demonstrating that our QAE achieves performance competitive with neural-network-based autoencoders while requiring fewer trainable parameters. We evaluate our model on datasets that closely reflect SAP system telemetry and show that the proposed QAE is a viable and efficient alternative for semisupervised AD in real-world enterprise settings. Anomaly Detection (AD) refers to the process of identifying patterns or events that deviate from typical - or normal - behavior [1]. It plays a critical role in IT security and many other domains, as anomalies often correspond to potential security breaches, frauds, or system failures [2], [3]. Modern enterprise infrastructure, such as SAP HANA Cloud and other large scale cloud native applications, rely on continuous monitoring to ensure optimal performance, availability, and reliability. With increasing system complexity and scale, observability platforms generate large volumes of telemetry data, including structured multivariate time series (MTS) and unstructured log streams.