Measurement-device-independent verification of quantum states
Xin-Yu Xu, Yi-Zheng Zhen, Qing Fa Zhou, Shu-Ming Hu, Jun-Hao Wei, Nuo-Ya Yang, Li Li, Nai-Le Liu, Kai Chen · Physical Review A · 2024
Efficient and reliable verification of quantum states is central to quantum information processing applications. If using well-characterized measurement devices, effective methods have been developed for quantum state verification (QSV). In reality, however, measurement devices are generally imperfect or untrusted, which limits significantly the application of standard QSV protocols. Here, we propose the measurement-device-independent QSV (MDI-QSV) scheme for practice. With the help of trusted quantum inputs, we have developed a systematical approach to design MDI-QSV strategies for an arbitrary pure target state. We find that the number of required measurements has an optimal scaling with required accuracy and confidence level, similar to the standard QSV where trusted measurement devices are available. Our results offer a sample-efficient and realistic method for quantum state verification with virtues of a measurement-device-independent manner, and are within reach of current technology.