Self-testing of a single quantum device under computational assumptions

Understand

Self-testing is a method to characterise an arbitrary quantum system based only on its classical input-output correlations, and plays an important role in device-independent quantum information processing as well as quantum complexity theory.

• Prior works on self-testing require the assumption that the system's state is shared among multiple parties that only perform local measurements and cannot communicate.
• Here, we replace the setting of multiple non-communicating parties, which is difficult to enforce in practice, by a single computationally bounded party.
• Specifically, we construct a protocol that allows a classical verifier to robustly certify that a single computationally bounded quantum device must have prepared a Bell pair and performed single-qubit measurements on it, up to a change of basis applied to both the device's state and measurements.