Self-induced superradiant masing

Area of Science:

• Quantum Optics
• Condensed Matter Physics
• Quantum Information Science

Background:

• Collective optical effects in superradiance typically assume independent emitters interacting via a common light mode.
• Direct dipole-dipole interactions are usually considered detrimental, causing decoherence in emitter ensembles.

Purpose of the Study:

• To investigate the role of direct spin-spin interactions in driving superradiant dynamics.
• To explore the behavior of a hybrid system comprising nitrogen-vacancy center spins in diamond coupled to a superconducting microwave cavity.

Main Methods:

• Experimental observation of superradiant dynamics in the hybrid system.
• Analysis of subsequent emission pulses and quasi-continuous masing.
• Microscopic simulations to confirm the driving mechanism.

Main Results:

• Observed a train of emission pulses and quasi-continuous masing after an initial superradiant burst, lasting up to one millisecond.
• Demonstrated that spectral hole refilling, driven by spin inversion redistribution, causes this behavior.
• Confirmed that direct dipole-dipole interactions, not other cavity effects, are responsible for the observed dynamics.

Conclusions:

• Direct spin-spin interactions can actively drive superradiance, contrary to conventional assumptions.
• The findings open avenues for studying complex spin interactions in disordered systems.
• Potential for developing ultranarrow-linewidth solid-state superradiant masers using microwave-driven spin control.