Phonon-induced population dynamics and intersystem crossing in nitrogen-vacancy centers

Area of Science:

• Quantum physics
• Materials science
• Solid-state physics

Background:

• Nitrogen-vacancy (NV) centers in diamond are promising for quantum technologies.
• Understanding excited-state dynamics is crucial for optimizing NV center performance.
• Phonon-induced mixing and intersystem crossing (ISC) are key processes affecting NV center coherence.

Purpose of the Study:

• To directly measure population dynamics in the excited state manifold of NV centers.
• To quantify phonon-induced mixing and ISC rates.
• To develop a unified theoretical model for these dynamics and explore its implications for sensing applications.

Main Methods:

• Direct measurement of population dynamics in NV centers.
• Quantification of phonon-induced mixing rates at varying temperatures.
• Measurement of intersystem crossing (ISC) rates for different excited states.
• Development and validation of a theoretical model unifying phonon-induced mixing and ISC.

Main Results:

• Population dynamics in the excited state manifold of NV centers were directly measured.
• Phonon-induced mixing was quantified and shown to be suppressible at low temperatures.
• A theoretical model was developed that accurately describes both phonon-induced mixing and ISC mechanisms.
• The model successfully predicts unknown elements of the NV center's electronic structure.

Conclusions:

• The developed theoretical model provides a unified understanding of phonon-induced mixing and ISC in NV centers.
• The ability to suppress phonon-induced mixing at low temperatures offers a pathway for improved control.
• The model's predictive power can guide the design of enhanced NV center-based quantum sensors.