Department of Solid State Physics, Faculty of Physics and Applied Informatics, University of Łódź, ulica Pomorska 149/153, 90-236 Łódź, Poland.
Int J Mol Sci. 2021 Dec 13;22(24):13364. doi: 10.3390/ijms222413364.
Recent experimental studies proved the presence of the triplet spin state in atomically precise heptauthrene nanostructure of nanographene type (composed of two interconnected triangles with zigzag edge). In the paper, we report the computational study predicting the possibility of controlling this spin state with an external in-plane electric field by causing the spin switching. We construct and discuss the ground state magnetic phase diagram involving S=1 (triplet) state, S=0 antiferromagnetic state and non-magnetic state and predict the switching possibility with the critical electric field of the order of 0.1 V/Å. We discuss the spin distribution across the nanostructure, finding its concentration along the longest zigzag edge. To model our system of interest, we use the mean-field Hubbard Hamiltonian, taking into account the in-plane external electric field as well as the in-plane magnetic field (in a form of the exchange field from the substrate). We also assess the effect of uniaxial strain on the magnetic phase diagram.
最近的实验研究证明，在原子精确的七嗪纳米结构（由两个相互连接的锯齿边缘三角形组成的纳米石墨烯类型）中存在三重态自旋态。在本文中，我们报告了一项计算研究，预测通过自旋开关可以通过施加面内电场来控制这种自旋状态的可能性。我们构建并讨论了包含 S=1（三重态）态、S=0 反铁磁态和非磁态的基态磁相图，并预测了临界电场约为 0.1 V/Å 的开关可能性。我们讨论了横跨纳米结构的自旋分布，发现其沿着最长的锯齿边缘集中。为了模拟我们感兴趣的系统，我们使用平均场 Hubbard 哈密顿量，考虑面内外部电场以及面内磁场（以基底的交换场形式）。我们还评估了单轴应变对磁相图的影响。
