Harnessing magnetic vortex oscillations for local microwave sources in qubit control

초록

In this study, we explore the potential of magnetic vortices and antivortices as novel sources for generating nanometer-scale microwave fields. Utilizing a single-spin scanning magnetometer based on diamond NV centers, we investigated both static and dynamic magnetic properties of a thin Permalloy square, focusing on the magnetization and vortex core responses. While static images revealed the standard magnetic configuration, we detected gigahertz-frequency ac fields strongly localized at the vortex core, as confirmed through optically detected magnetic resonance contrast and Rabi frequency imaging. We attribute this observation to the dynamic circular motion of the vortex core and its associated oscillatory behavior. Simulations based on the OBJECT ORIENTED MICROMAGNETIC FRAMEWORK (OOMMF) and the Landau-Lifshitz-Gilbert equation demonstrate that vortices and antivortices can generate gigahertz microwave fields that are several orders of magnitude more intense than external driving fields, with spatial localization on the scale of tens of nanometers. This research opens new possibilities for generating powerful localized microwave fields that could effectively manipulate NV spin states, offering promising applications in quantum information processing and multi-NV quantum registers for advanced sensing.

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