Robust self-testing of the three-qubit W state

Self-testing is a device-independent method which can be used to determine the nature of a physical system or device, without knowing any detail of the inner mechanism or the physical dimensions of the Hilbert space of the system. The only information required comprises the number of measurements, the number of outputs of each measurement, and the statistics of each measurement. Earlier works on self-testing were restricted either to a two-party scenario or multipartite graph states. Here we construct a method to self-test the three-qubit W state and show how to extend it to other pure three-qubit states. Our bounds are robust against the inevitable experimental errors.