Measuring the Optical Concurrence of Vector Beams with an Atomic-State Interferometer

Area of Science:

• Quantum optics
• Atomic physics
• Quantum information science

Background:

• Vector beams exhibit correlations between polarization and spatial properties.
• Interactions between light and cold atoms are crucial for quantum information processing.

Purpose of the Study:

• To investigate the transmission of polarization-entangled vector beams through cold atoms.
• To establish a link between optical correlations and atomic spin states.
• To develop a method for measuring optical entanglement using atomic absorption.

Main Methods:

• Transmission of vector beams through cold atoms under a transverse magnetic field.
• Analysis of phase-dependent atomic dynamics.
• Measurement of absorption profiles to observe interference fringes.

Main Results:

• Spatially varying polarization of vector beams is imprinted onto atomic spin polarizations.
• A direct link between optical space-polarization correlations and atomic-state interference is established.
• Absorption profiles reveal interference fringes whose modulation strength quantifies optical concurrence.

Conclusions:

• Optical concurrence can be identified from a single absorption image.
• The findings offer new avenues for quantum memories, metrology, and spintronics.
• This work bridges optical entanglement and atomic spin dynamics.