Reconstructing Gaussian bipartite states with a single polarization-sensitive homodyne detector

Area of Science:

• Quantum optics
• Quantum information science
• Quantum state tomography

Background:

• Characterizing quantum states is crucial for quantum information processing.
• Bipartite Gaussian states are fundamental in quantum optics and quantum information.
• Conventional methods often require complex setups and introduce losses.

Purpose of the Study:

• To present a novel and simplified method for fully estimating Gaussian bipartite polarization states.
• To reduce experimental complexity and optical losses in quantum state characterization.
• To provide an intuitive explanation of the proposed measurement scheme.

Main Methods:

• Utilizing a single homodyne detector for quantum state estimation.
• Performing six independent measurements to gather state information.
• Reconstructing the covariance matrix of the quantum state.

Main Results:

• Successfully estimated Gaussian bipartite polarization states with a single detector.
• Circumvented the need for additional optics, minimizing signal path losses.
• Demonstrated the method's validity by comparison with a dual-homodyne scheme.

Conclusions:

• The proposed method offers a more efficient and less lossy approach to characterizing Gaussian bipartite polarization states.
• This technique simplifies experimental requirements for quantum state tomography.
• The findings contribute to advancements in practical quantum state estimation.