Strong Photon-Magnon Coupling Using a Lithographically Defined Organic Ferrimagnet

Area of Science:

• Quantum physics
• Materials science
• Condensed matter physics

Background:

• Integrating low-damping magnetic systems with superconducting circuits presents scalability challenges.
• Organic-based magnets offer potential for low-temperature processing and patterning.
• Cavity-magnonic systems are crucial for hybrid quantum technologies.

Purpose of the Study:

• To demonstrate a cavity-magnonic system using vanadium tetracyanoethylene (V[TCNE]x).
• To investigate the integration of ultra-low damping magnetic materials with superconducting circuits.
• To explore the potential for scalable quantum circuit fabrication using magnonic components.

Main Methods:

• Fabrication of a superconducting microwave resonator coupled to V[TCNE]x magnon modes.
• Characterization of the cavity-magnonic system at low temperatures (T≈0.4 K).
• Utilizing electron beam lithography for patterning the V[TCNE]x material.

Main Results:

• Successful demonstration of strong coupling regime with cooperativity exceeding 1000.
• Observation of coupling between the Kittel mode and the resonator mode.
• Identification of higher-order magnon modes with significantly narrower linewidths.

Conclusions:

• V[TCNE]x is a promising material for scalable quantum circuit integration due to its low damping and processing compatibility.
• The demonstrated cavity-magnonic system achieves high cooperativity, suitable for quantum applications.
• This work enables the design and fabrication of magnonic circuits comparable to electrical wiring for hybrid quantum devices.