Reliable experimental certification of one-way Einstein-Podolsky-Rosen steering

Quantum steering is a recently-defined form of quantum correlation which lays at the heart of quantum mechanics. In difference from other types of quantum correlations, quantum steering is inherently asymmetric, which presents in one direction but may not in the other direction in a bipartite system. Recently, a conclusive experimental demonstration of this directional nature of quantum steering has been carried out, yet requires a crucial use of a qutrit party to overcome the ambiguous assumptions exsiting in previous experiments. Therefore, a reliable experimental certification of one-way steering in genuine qubit systems still remains an challenging question. Here, we report such an experiment demonstrating one-way steering for the two-qubit entangled system based on a newly-developed orbital angular momentum platform. Our scheme and results thus resolve the subtlety in the dimensionality and further the ambiguity in existing data of previous demonstrations, and provide a universal method to characterize one-way steering effect for two-qubit states.