Experimental Certification of Nonclassicality via Phase-Space Inequalities

Area of Science:

• Quantum optics
• Quantum information science
• Experimental quantum physics

Background:

• Experimental certification of quantum nonclassicality is crucial but challenging in realistic systems with noise and losses.
• Existing methods may fail to detect nonclassicality in the presence of significant experimental imperfections.

Purpose of the Study:

• To experimentally implement and validate novel phase-space inequalities for certifying nonclassicality.
• To demonstrate the practicality and sensitivity of this new approach for noisy and lossy quantum states of light.

Main Methods:

• Experimental generation of single-photon-added thermal states with varying thermal mean photon numbers.
• Reconstruction of Wigner and Husimi Q functions for the generated quantum states.
• Application of phase-space inequalities to certify nonclassicality under different loss levels.

Main Results:

• The implemented phase-space inequalities successfully detected nonclassicality in noisy and lossy quantum states.
• Nonclassicality was identified even with high loss levels (up to 93%) and when other methods were ineffective.
• The method proved sensitive and practical for realistic quantum state characterization.

Conclusions:

• The novel phase-space inequalities offer a robust and sensitive tool for experimental nonclassicality certification.
• This approach enhances the capability to characterize quantum states in realistic quantum technologies.
• Potential for wide applicability in advancing quantum science and technology is highlighted.