Cryogenic hybrid magnonic circuits based on spalled YIG thin films

TL;DR

This paper demonstrates a method to produce cryogenic YIG thin films by spalling from GGG substrates, enabling improved hybrid magnonic devices for quantum information processing with reduced microwave loss.

Contribution

It introduces a novel spalling technique to separate YIG films from GGG substrates, enhancing the integration of magnonic devices at cryogenic temperatures.

Findings

Successful spalling of YIG thin films validated by hybrid device measurements.

Strong magnon-photon coupling demonstrated in superconducting resonator devices.

Reduced microwave loss in spalled YIG films at cryogenic temperatures.

Abstract

Yttrium iron garnet (YIG) magnonics has garnered significant research interest because of the unique properties of magnons (quasiparticles of collective spin excitation) for signal processing. In particular, hybrid systems based on YIG magnonics show great promise for quantum information science due to their broad frequency tunability and strong compatibility with other platforms. However, their broad applications have been severely constrained by substantial microwave loss in the gadolinium gallium garnet (GGG) substrate at cryogenic temperatures. In this study, we demonstrate that YIG thin films can be spalled from YIG/GGG samples. Our approach is validated by measuring hybrid devices comprising superconducting resonators and spalled YIG films, which exhibits anti-crossing features that indicate strong coupling between magnons and microwave photons. Such new capability of separating YIG thin films from GGG substrates via spalling, and the integrated superconductor-YIG devices represent a significant advancement for integrated magnonic devices, paving the way for advanced magnon-based coherent information processing.