Stability optimization based on high-resolution spatial thermal distribution of a single <sup>174</sup>Yb<sup>+</sup> ion

Trapped ion systems play a vital role in fields such as quantum information processing and optical frequency standards. Low-energy, highly stable trapped ions enable precise quantum manipulation and significantly reduce Doppler effect. However, ion heating presents a major challenge to maintaining such stability. In our work, a high-magnification optical imaging system is employed to achieve micron-level resolution imaging of a single ¹⁷⁴Yb⁺ ion crystal. By analyzing the ion's spatial thermal distribution and applying an adaptive Gaussian filtering technique, the root mean square linewidth is accurately extracted, enabling accurate temperature measurements. Experimentally, the temperature (or energy) of a single ¹⁷⁴Yb⁺ ion is progressively reduced from 1 400 mK to 260 mK. Various heating mechanisms become increasingly apparent as the ion temperature decreases. These findings provide a foundation for further optimization of ion stability. This study not only presents a practical approach for evaluating and reducing the temperature of trapped ions, thereby improving their stability, but also paves the way for exploring other ion heating effects.