Ultranarrow Superradiant Lasing by Dark Atom-Photon Dressed States.

Area of Science:

• Atomic physics
• Quantum optics
• Laser spectroscopy

Background:

• Optical lattice clocks are crucial for high-precision timekeeping and fundamental physics tests.
• Achieving narrow linewidths in laser sources is essential for improving clock stability and accuracy.
• Incoherent pumping methods offer an alternative approach to laser generation in atomic systems.

Purpose of the Study:

• To investigate the generation of narrow-linewidth laser light via incoherent pumping in an optical lattice clock.
• To understand the underlying physical mechanisms responsible for the observed narrow linewidth.
• To explore the role of magnetic fields in controlling light generation in ultracold atomic systems.

Main Methods:

• Utilizing ultracold strontium-88 atoms in an optical lattice.
• Employing incoherent optical pumping to excite the atomic system.
• Applying a magnetic field to influence atom-light interactions.
• Measuring the linewidth of the generated laser light.

Main Results:

• Demonstrated laser light production with an exceptionally narrow linewidth of approximately 10 Hz.
• Observed linewidth significantly narrower than cavity linewidth and atomic decay/excitation rates.
• Identified the narrow lasing as a result of multiatom superradiant effects.
• Confirmed the crucial role of magnetic field-induced coupling between bright and dark atomic states.

Conclusions:

• Incoherent pumping in strontium-88 optical lattice clocks, combined with a magnetic field, can produce ultra-narrow linewidth laser light.
• The observed narrow linewidth is attributed to a synergistic interplay of superradiance and magnetic field-controlled dressed states.
• This technique offers a promising pathway for developing more precise atomic clocks and exploring quantum phenomena.