Faraday-Shielded dc Stark-Shift-Free Optical Lattice Clock

Area of Science:

• Atomic physics
• Quantum optics
• Metrology

Background:

• Optical lattice clocks are crucial for precise timekeeping.
• DC Stark shifts caused by stray electric fields can limit clock accuracy.
• Faraday shields are used to mitigate these electric fields.

Purpose of the Study:

• To demonstrate the absence of a DC Stark shift in an ytterbium optical lattice clock.
• To experimentally validate the effectiveness of an in-vacuum Faraday shield.
• To identify and address potential errors in Stark shift cancellation strategies.

Main Methods:

• Implementing an in-vacuum Faraday shield to suppress stray electric fields.
• Applying high voltage to electrodes to diagnose shielding effectiveness.
• Measuring the DC Stark shift to a precision of 10^{-20} relative to the clock frequency.

Main Results:

• The DC Stark shift was found to be absent within the measurement precision.
• The Faraday shield effectively suppressed stray electric fields.
• A potential error source due to field gradients and atomic extent was identified.

Conclusions:

• Faraday shielding is a practical and effective solution for eliminating DC Stark shifts in optical lattice clocks.
• Experimental validation is essential for confirming shielding performance.
• Consideration of field gradients is important for accurate Stark shift cancellation.