A self-consistent micromagnetic model is proposed for simulating interactions between a superparamagnetic label particle and a low-noise GMR vortex sensor, focusing on most common operations such as label detection and saturation. For this purpose, we evaluate the combined action of vortex stray field and the applied external field.

By solving the Landau–Lifshitz-Gilbert equation we find that a superparamagnetic label with a diameter of 60 nm can be successfully detected by a magnetic vortex structure assisted with an external magnetic field of 100 mT. Subsequently, the self-consistent spin diffusion model is applied to calculate electric response of a standard low-noise GMR vortex sensor to the presence of magnetically-saturated label. It is shown that the stray field of the activated label produces a detectable potential difference in the GMR sensor of 27.1 to 27.8 mV, the magnitude of which depends on location of the label with respect to the sensor surface.

提出了一种自洽微磁模型，用于模拟超顺磁标签粒子与低噪声 GMR 涡流传感器之间的相互作用，重点关注最常见的操作，如标签检测和饱和。为此，我们评估涡流杂散场和施加的外部场的组合作用。

通过求解 Landau-Lifshitz-Gilbert 方程，我们发现在 100 mT 的外部磁场的辅助下，磁性涡旋结构可以成功检测到直径为 60 nm 的超顺磁性标签。随后，自洽自旋扩散模型用于计算标准低噪声 GMR 涡流传感器对磁饱和标签存在的电响应。结果表明，激活标记的杂散场在 GMR 传感器中产生 27.1 到 27.8 mV 的可检测电位差，其大小取决于标记相对于传感器表面的位置。