Gallium Phosphide as a Piezoelectric Platform for Quantum Optomechanics

Area of Science:

• Quantum optics
• Solid-state physics
• Nanotechnology

Background:

• Quantum states of mechanical oscillators are advancing, with applications in fundamental and applied quantum science.
• Piezoelectric optomechanical devices coupled to microwave circuits show promise for quantum transduction.
• Challenges like optical absorption and low quality factors have hindered quantum regime operation.

Purpose of the Study:

• To design and characterize a novel piezoelectric optomechanical device for quantum transduction.
• To overcome limitations of previous devices, enabling quantum behavior.

Main Methods:

• Fabrication of a piezoelectric optomechanical device using gallium phosphide.
• Coupling a 2.9 GHz mechanical mode to a high-quality factor optical resonator in the telecom band.
• Characterization of the device's optical and mechanical properties.

Main Results:

• Demonstrated quantum behavior in the gallium phosphide optomechanical device.
• Achieved low optical absorption comparable to silicon devices.
• Integrated a 2.9 GHz mechanical mode with a telecom-band optical resonator.

Conclusions:

• Gallium phosphide is a suitable material for quantum optomechanical devices.
• The device enables noise-free quantum transduction between microwave and optical systems.
• Potential for transduction from visible color centers to the telecom band.