Ultrasensitive Atomic Comagnetometer with Enhanced Nuclear Spin Coherence.

Area of Science:

• Atomic, Molecular, and Optical Physics
• Condensed Matter Physics
• Precision Measurements

Background:

• Alkali-noble-gas comagnetometers offer high energy resolution for fundamental research.
• Understanding spin relaxation mechanisms is crucial for improving sensor performance.

Purpose of the Study:

• Identify novel spin relaxation mechanisms in comagnetometers.
• Enhance nuclear spin hyperpolarization and transverse coherence time.
• Achieve ultrahigh inertial rotation sensitivity for precision measurements.

Main Methods:

• Investigated a new relaxation mechanism: the gradient of the Fermi-contact-interaction field.
• Employed optimal hybrid optical pumping for precise spin distribution control.
• Operated a ^{21}Ne-Rb-K comagnetometer in a self-compensation regime.

Main Results:

• Discovered a dominant relaxation mechanism for hyperpolarized nuclear spins.
• Achieved a tenfold increase in nuclear spin hyperpolarization and transverse coherence time.
• Demonstrated ultrahigh inertial rotation sensitivity of 3×10^{-8} rad/s/Hz^{1/2}.

Conclusions:

• The new relaxation mechanism provides a pathway for enhanced comagnetometer performance.
• The developed ^{21}Ne-Rb-K comagnetometer offers unprecedented sensitivity for detecting exotic spin-dependent interactions.
• Projected sensitivity exceeds previous limits by over 4 orders of magnitude, opening new avenues in fundamental physics.