Experimental sample-efficient and device-independent GHZ state certification

Area of Science:

• Quantum Information Science
• Quantum Cryptography
• Quantum Computing

Background:

• Quantum resource certification is crucial for secure quantum information processing.
• Device-independent (DI) self-testing methods are used for verification but often require many samples (asymptotic, IID).
• Existing DI methods face limitations in practical experimental implementation due to sample requirements.

Purpose of the Study:

• To overcome limitations of asymptotic and IID assumptions in device-independent quantum state verification.
• To enable robust quantum state certification using a minimal number of quantum resource copies.
• To demonstrate efficient and device-independent certification of multipartite entangled states.

Main Methods:

• Developed a theoretical protocol for quantum state certification in the few-copies and non-IID regime.
• Utilized a high-fidelity multipartite entangled photon source for experimental implementation.
• Applied device-independent self-testing principles to a single copy of a quantum state.

Main Results:

• Successfully demonstrated efficient and device-independent certification of a four-qubit Greenberger-Horne-Zeilinger (GHZ) state.
• Overcame the challenges posed by few-copy and non-IID data requirements in quantum verification.
• Showcased the practical feasibility of DI quantum state certification.

Conclusions:

• The developed protocol enables reliable quantum state verification under realistic experimental conditions.
• This work paves the way for robust and trustworthy quantum information processing applications.
• Efficient DI certification of quantum states is achievable, enhancing the security of quantum technologies.