Oral: Towards Topological Magnons for Hybrid Magnonic Systems

Magnonic quantum hybrid systems have been proposed as a scheme to couple and entangle solid-state spin centers over micrometer lengths [1,2], improving the potential use of spin centers for quantum technologies. However, the required operating temperature for these hybrid schemes is ∼100mK, mainly due to the noise susceptibility of the magnetic excitations at high temperatures. This makes these systems less practical, barring their widespread application. Recently, it has been shown that one can harness the edge state localization of topological magnons to entangle spin qubits [3]. Here, we study the implementation of topological magnon modes for the entanglement of NV center qubits, paying special attention to the effect of differing edge state terminations. We begin by deriving topological magnons in 2D honeycomb ferromagnets in the presence of nearest neighbor and next nearest neighbor exchange, Dzyaloshinskii–Moriya interactions, and easy-axis anisotropy. Next, we develop a formalism for determining the coupling strength and relaxation time for NV-magnon interactions in bulk honeycomb ferromagnets. Finally, we present our results on the coupling between NV centers and topological magnons in different nanoribbons, and comment on how this formalism allows us to predict the fingerprint of topological magnons via quantum sensors.

[1] D. R. Candido et al 2021 Mater. Quantum. Technol. 1 011001

[2] M. Fukami et al PRX Quantum 2, 040314 (2021)

[3] B. Hetényi et al Phys. Rev. B 106, 235409 (2022)