Ramsey Spectroscopy with Displaced Frequency Jumps

Area of Science:

• Atomic physics
• Metrology
• Spectroscopy

Background:

• Advanced Ramsey-based protocols aim to improve atomic clock precision by minimizing frequency shifts.
• Coherent Population Trapping (CPT) is a key technique in cold-atom microwave clocks.

Purpose of the Study:

• To propose a simplified alternative to autobalanced Ramsey interrogation protocols.
• To demonstrate the application of this new method to a CPT cold-atom microwave clock.

Main Methods:

• The proposed method uses two consecutive Ramsey sequences with varying dark periods.
• Frequency jumps are precisely controlled by a displacement parameter, inversely proportional to the dark period.
• The local oscillator frequency serves as a single control variable for servo loops.

Main Results:

• The displaced frequency-jump Ramsey (DFJR) scheme simplifies implementation by using a single physical variable (LO frequency).
• DFJR avoids noise associated with LO phase control.
• Testing on a CPT cold-atom clock showed over an order of magnitude reduction in light shift sensitivity compared to standard Ramsey interrogation.

Conclusions:

• The DFJR method offers a simpler and more robust approach to Ramsey spectroscopy.
• This technique enhances the stability and precision of atomic clocks.
• The DFJR method is applicable to various Ramsey-spectroscopy applications, including frequency metrology and precision spectroscopy.