Wang Xiaoli, Zhu Xinru, Wu Ping, Li Qing, Li Zhen, Zhang Xiaolei, Liu Zhongmin, Zhang Yuexing, Du Pengli
Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China.
College of Chemical Engineering, Qinghai University, Xining 810016, PR China.
J Phys Chem A. 2024 Jun 13;128(23):4750-4760. doi: 10.1021/acs.jpca.4c02067. Epub 2024 Jun 4.
The interactions between a magnetic tip and local spin impurities initiate unconventional Kondo phenomena, such as asymmetric suppression or even splitting of the Kondo peak. However, a lack of realistic theoretical models and comprehensive explanations for this phenomenon persists due to the complexity of the interactions. This research employs a joint method of density functional theory (DFT) and hierarchical equation of motion (HEOM) to simulate and contrast the modulation of the spin state and Kondo behavior in the Fe/Cu(100) system with two distinct magnetic tips. A cobalt tip, possessing a larger magnetic moment, incites greater atomic displacement of the iron atom, more notable alterations in electronic structure, and enhanced charge transfer with the environment compared with the control process utilizing a nickel tip. Furthermore, the Kondo resonance undergoes asymmetric splitting as a result of the ferromagnetic correlation between the iron atom and the magnetic tip. The Co tip's higher spin polarization results in a wider spacing between the splitting peaks. This investigation underscores the precision of the DFT + HEOM approach in predicting complex quantum phenomena and explaining the underlying physical principles. This provides valuable theoretical support for developing more sophisticated quantum regulation experiments.
磁性尖端与局部自旋杂质之间的相互作用引发了非常规的近藤现象，例如近藤峰的不对称抑制甚至分裂。然而，由于相互作用的复杂性，对于这一现象仍缺乏现实的理论模型和全面的解释。本研究采用密度泛函理论（DFT）和运动方程分层法（HEOM）相结合的方法，模拟并对比了具有两种不同磁性尖端的Fe/Cu(100)系统中自旋态的调制和近藤行为。与使用镍尖端的对照过程相比，具有更大磁矩的钴尖端会引起铁原子更大的原子位移、更显著的电子结构变化以及与环境更强的电荷转移。此外，由于铁原子与磁性尖端之间的铁磁相关性，近藤共振发生不对称分裂。钴尖端较高的自旋极化导致分裂峰之间的间距更宽。这项研究强调了DFT + HEOM方法在预测复杂量子现象和解释潜在物理原理方面的精确性。这为开展更复杂的量子调控实验提供了有价值的理论支持。
