Hybrid quantum systems with high-T[Formula: see text] superconducting resonators

Area of Science:

• Condensed Matter Physics
• Quantum Optics
• Materials Science

Background:

• Superconducting microwave resonators are key components in microwave circuits.
• High-temperature cuprate superconductors offer advantages over conventional low-temperature superconductors for wider operating ranges.
• Developing functional circuits and hybrid quantum systems requires advanced resonator technologies.

Purpose of the Study:

• To realize and characterize high-temperature superconducting coplanar waveguide resonators.
• To investigate the performance of these resonators in electron spin resonance (ESR) measurements.
• To explore spin-cavity hybridization and magnetic coupling in molecular spin ensembles.

Main Methods:

• Fabrication of high-temperature superconducting coplanar waveguide resonators.
• Tuning resonator coupling regimes (undercoupled to overcoupled) via device geometry.
• Performing electron spin resonance (ESR) measurements on a molecular spin ensemble.
• Analyzing temperature-dependent Rabi splitting and spin relaxation times.

Main Results:

• Successful realization of high-temperature superconducting coplanar waveguide resonators.
• Demonstration of tunable coupling regimes, from lossy to lossless.
• Observation of spin-cavity hybridization indicating coherent coupling between microwave fields and spins.
• Evidence of antiferromagnetic coupling in the molecular spin ensemble below 2 K.

Conclusions:

• High-temperature superconducting resonators are promising for developing advanced functional circuits.
• These resonators offer novel approaches for creating hybrid quantum systems.
• The study demonstrates a new method for electron spin resonance measurements across a broad range of temperatures and magnetic fields.