Coherent population trapping based atomic reservoir for almost perfect higher-order squeezing

Area of Science:

• Quantum Optics
• Atomic Physics
• Quantum Information

Background:

• Coherent population trapping (CPT) is a quantum interference effect used in atomic physics.
• Dissipative interactions in CPT systems can lead to squeezing of optical fields.
• Higher-order squeezing goes beyond traditional second-order squeezing by involving higher-order moments.

Purpose of the Study:

• To investigate higher-order squeezing beyond second-order in CPT-based systems.
• To explore the role of dissipative interactions in achieving advanced squeezing levels.
• To evaluate the robustness of the mechanism against spontaneous emission.

Main Methods:

• Utilizing coherent population trapping (CPT) based atomic reservoirs.
• Analyzing the dissipative evolution of Bogoliubov modes.
• Employing criteria involving higher-order moments to quantify squeezing.
• Comparing CPT systems with traditional two-level atomic systems.

Main Results:

• CPT-based atomic reservoirs facilitate the evolution of Bogoliubov modes towards vacuum states.
• Achieved nearly perfect fourth-order squeezing (90%-100%).
• The mechanism demonstrates robustness against spontaneous emission due to atoms remaining in ground states.

Conclusions:

• CPT-based dissipative interactions provide an effective route to high-order optical field squeezing.
• The presented method offers a robust and efficient way to generate significant fourth-order squeezing.
• CPT systems show advantages over two-level atoms for achieving higher-order squeezing.