English

Macroscopic entanglement between two magnon modes via two-tone driving of a superconducting qubit

Quantum Physics 2026-05-08 v1 Mesoscale and Nanoscale Physics Optics

Abstract

The cavity-mediated coupling between magnons in an yttrium-iron-garnet (YIG) sphere and a superconducting qubit has recently been demonstrated as a new platform for preparing macroscopic quantum states. Here, based on this system, we propose to entangle two magnon modes in two YIG spheres by driving the qubit with a two-tone field and by appropriately choosing the frequencies and strengths of the two driving fields. We show that strong entanglement can be achieved with fully feasible parameters. We further provide a detection scheme for experimentally verifying the entanglement. Our results indicate that macroscopic entanglement between two magnon modes in two millimeter-sized YIG spheres, involving more than 101810^{18} spins, can be realized using currently available parameters, which finds promising applications in fundamental studies, such as macroscopic quantum mechanics and the test of unconventional decoherence theories.

Keywords

Cite

@article{arxiv.2605.06297,
  title  = {Macroscopic entanglement between two magnon modes via two-tone driving of a superconducting qubit},
  author = {Rong-Can Yang and Gang Liu and Gen Li and Jie Li},
  journal= {arXiv preprint arXiv:2605.06297},
  year   = {2026}
}