This article presents a novel classical-quantum anomaly detection model based on density estimation and the expected values of density matrices. The core subroutine of the proposed method is a qubit-based quantum protocol whose task is to compute the expected value of a density matrix, being flexible enough to support the use of pure and mixed states approaches. The anomaly detection model is tested with pure and mixed states on a synthetic data set for density estimation and on a widely used

more »

... al-life data set for anomaly detection; results show higher accuracy with mixed states for both tasks.