2025/09/29 by Mael Demarets, A. M. Vadiraj, Demarets, M. +5 · 1 citation
Engineering · #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Magnetic Bearings and Levitation Dynamics #Magnetic Field Sensors Techniques #Magneto-Optical Properties and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2509.24551
openalex publication_date 2025/09/29 · openalex created_date 2025/10/19 · openalex updated_date 2026/07/30
Isolators are commonly found in the amplification chain of microwave setups to shield sensitive devices such as superconducting qubits from noise and back-scattered signals. Conventional ferrite-based isolators are bulky, lossy and rely on strong magnetic fields, which pose challenges for their co-integration in large-scale superconducting devices. Although several magnetless approaches based on parametric modulation have been explored to overcome these limitations, none has yet experimentally demonstrated wideband isolation on par with ferrite devices. Here, we propose a compact modulation-based isolator that achieves large isolation bandwidth using a dispersion-engineered transmission line. The engineered line forms an effective two-mode system that enables broadband isolation by supporting adiabatic mode conversion over a wide instantaneous bandwidth. Numerical simulations show that this architecture can provide more than 20 dB isolation across 4 - 8 GHz, matching the performance of ferrite-based isolators. Moreover, we propose an on-chip superconducting device implementation that shows promise against parameter variations and enables a scalable path for co-integration with future large-scale superconducting systems.