Entanglement detection is one of the most conventional tasks in quantum information processing. While most experimental demonstrations of high-dimensional entanglement rely on fidelity-based witnesses, these are powerless to detect entanglement within a large class of entangled quantum states, the so-called unfaithful states. In this paper, we introduce a highly flexible automated method to construct optimal tests for entanglement detection given a bipartite target state of arbitrary dimension, faithful or unfaithful, and a set of local measurement operators. By restricting the number or complexity of the considered measurement settings, our method outputs the most convenient protocol to test the entanglement of the target state in the lab. Using the 3-setting protocols generated by our method, we experimentally certify 2-and 3-dimensional entanglement in 4-dimensional unfaithful states.
I. INTRODUCTIONEntanglement is the bedrock of most quantum information processing protocols (Gühne and Tóth, 2009; Horodecki et al., 2009). It is a key resource in quantum teleportation (Bennett et al., 1993), entanglement-based quantum key distribution (QKD) (Yin et al., 2017) and quantum communication complexity (Buhrman et al., 2010). Generating high-quality entangled states and detecting them reliably is a crucial prerequisite to conduct any quantum communication task.