Improvement of an Atomic Clock using Squeezed Vacuum

Area of Science:

• Atomic Physics
• Quantum Metrology
• Precision Measurement

Background:

• Atom interferometers are crucial for precision metrology, particularly in realizing the second.
• Classical atom interferometers are limited by vacuum noise, restricting precision to the standard quantum limit (SQL).
• Microwave fountain clocks, the current time standard, are significantly impacted by the SQL.

Purpose of the Study:

• To propose and experimentally demonstrate a novel atomic clock configuration.
• To overcome the standard quantum limit (SQL) in atom interferometers.
• To enhance the sensitivity and precision of atomic clocks for timekeeping.

Main Methods:

• Utilized a novel clock configuration employing squeezed vacuum states.
• Prepared a squeezed vacuum state with an average of 0.75 atoms.
• Experimentally demonstrated the proposed configuration with a large ensemble of 10000 atoms.

Main Results:

• Achieved a clock sensitivity improvement of 2.05 dB above the standard quantum limit (SQL).
• Successfully demonstrated surpassing the SQL using squeezed vacuum states in an atomic interferometer.
• The squeezed vacuum state contained an average of 0.75 atoms, enhancing the sensitivity of 10000 atoms.

Conclusions:

• The novel clock configuration effectively surpasses the standard quantum limit (SQL).
• Squeezed vacuum states offer a viable method to enhance atomic clock sensitivity.
• This research paves the way for next-generation atomic fountain clocks with improved precision.