Nonreciprocal reconfigurable microwave optomechanical circuit.

Area of Science:

• Quantum Optics
• Solid State Physics
• Microwave Engineering

Background:

• Nonreciprocal devices are crucial for radar, radio communication, and superconducting quantum circuits.
• Traditional devices use ferrites, requiring bulky and lossy magnetic fields.
• Magnetic-field-free alternatives are sought, with Josephson nonlinearity being a recent approach.

Purpose of the Study:

• To realize reconfigurable nonreciprocal microwave transmission without magnetic fields.
• To explore optomechanical interactions in superconducting electromechanical circuits for nonreciprocity.
• To analyze the performance and potential applications of this novel approach.

Main Methods:

• Utilizing purely optomechanical interactions in a superconducting electromechanical circuit.
• Employing interference between two mechanical modes to mediate microwave coupling.
• Analyzing isolation, transmission, and noise properties of the developed circuit.

Main Results:

• Demonstrated reconfigurable nonreciprocal transmission between two microwave modes.
• Achieved magnetic-field-free operation, overcoming limitations of traditional devices.
• Showcased the potential for realizing quantum-limited circulators and directional amplifiers.

Conclusions:

• Purely optomechanical nonreciprocity offers a promising magnetic-field-free alternative.
• The demonstrated principle can be extended to various microwave and quantum devices.
• This work lays the foundation for topological states of light and sound.