Chip-integrated plasmonic cavity-enhanced single nitrogen-vacancy center emission

Area of Science:

• Quantum optics
• Solid-state physics
• Nanophotonics

Background:

• Nitrogen-vacancy (NV) centers in diamond are promising room-temperature quantum emitters due to their stability and spin dynamics.
• Broad emission bandwidth of NV centers limits their efficiency in quantum applications.
• Efficient coupling of NV centers to optical modes is crucial for enhanced light-matter interaction.

Purpose of the Study:

• To demonstrate chip-integrated cavity-coupled emission of NV centers into propagating surface plasmon polariton (SPP) modes.
• To narrow the NV center's emission bandwidth and enhance coupling efficiency.
• To achieve high decay rate enhancement of spontaneous emission.

Main Methods:

• Fabrication of a cavity resonator with distributed Bragg mirrors integrated with a dielectric-loaded SPP waveguide (DLSPPW).
• Utilized electron-beam lithography on silver-coated silicon substrates.
• Characterized cavity quality factor and resonance tunability.

Main Results:

• Demonstrated a cavity with a quality factor of ~70 (FWHM ~10 nm) and tunable resonance wavelength.
• Achieved up to a 42-fold enhancement in the decay rate of spontaneous emission at cavity resonance.
• Indicated high DLSPPW mode confinement for efficient light-matter interaction.

Conclusions:

• Chip-integrated DLSPPW cavities effectively enhance NV center emission efficiency and control spectral properties.
• This approach offers a pathway for developing advanced quantum devices utilizing NV centers.
• The demonstrated method shows potential for improved performance in quantum sensing and information processing.