High photon-phonon pair generation rate in a two-dimensional optomechanical crystal

Area of Science:

• Quantum physics
• Optomechanics
• Nanotechnology

Background:

• Integrated optomechanical systems are crucial for quantum information tasks.
• Residual optical heating limits current system performance.

Purpose of the Study:

• To demonstrate a novel 2D optomechanical crystal (OMC) geometry.
• To improve thermalization and achieve ground-state cooling of mechanical modes.
• To explore applications in quantum information processing and microwave-to-optical transduction.

Main Methods:

• Fabrication of a 2D optomechanical crystal (OMC) with enhanced thermal anchoring.
• Characterization of mechanical mode frequency (7.4 GHz) and optomechanical coupling rates (g₀/2π ≈ 880 kHz).
• Achieved ground-state cooling of the acoustic mode from 3 K to n_m = 0.32.

Main Results:

• Demonstrated eight times better thermalization compared to 1D OMCs.
• Achieved optomechanical strong-coupling regime with high optical quality factors (Q_opt = 2.4 × 10⁵).
• Showcased ground-state operation (n_m < 0.45) below 10 mK with 3 MHz repetition rates, generating photon-phonon pairs.

Conclusions:

• The new 2D OMC geometry significantly enhances thermalization and cooling capabilities.
• This work provides a robust foundation for advanced microwave-to-optical transducers.
• Achieved entanglement rates surpass current superconducting qubit decoherence rates, paving the way for quantum technologies.