A single-atom 3D sub-attonewton force sensor

Area of Science:

• Quantum physics
• Atomic physics
• Metrology

Background:

• Forces are fundamental to physical interactions, necessitating high-sensitivity measurement techniques.
• Laser-cooled trapped atomic ions offer a controllable quantum system ideal for precision metrology due to their properties.

Purpose of the Study:

• To demonstrate a novel three-dimensional force sensor with sub-attonewton sensitivity.
• To leverage super-resolution imaging of a single trapped ion for enhanced force detection.

Main Methods:

• Utilizing a single laser-cooled trapped ion as the sensing element.
• Employing super-resolution imaging to measure ion displacement in three dimensions with nanometer precision.
• Detecting forces by quantifying the ion's positional changes.

Main Results:

• Achieved sub-attonewton force sensitivities: 372 ± 9, 347 ± 18, and 808 ± 51 zN/m.
• Demonstrated sensitivities significantly exceeding the quantum limit (24×, 87×, and 21×).
• Successfully measured a 95-zN light pressure force, validating the sensor's performance.

Conclusions:

• The developed sensor provides unprecedented sensitivity for force measurement.
• This technique advances the field of precision metrology and quantum sensing.
• The sensor's ability to measure light pressure forces has implications for optical sensor calibration.