Manaparambil Anand, Weymann Ireneusz
Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland.
Sci Rep. 2021 Apr 28;11(1):9192. doi: 10.1038/s41598-021-88373-7.
In this paper we investigate the spin-resolved thermoelectric properties of strongly correlated molecular junctions in the linear response regime. The magnetic molecule is modeled by a single orbital level to which the molecular core spin is attached by an exchange interaction. Using the numerical renormalization group method we analyze the behavior of the (spin) Seebeck effect, heat conductance and figure of merit for different model parameters of the molecule. We show that the thermopower strongly depends on the strength and type of the exchange interaction as well as the molecule's magnetic anisotropy. When the molecule is coupled to ferromagnetic leads, the thermoelectric properties reveal an interplay between the spin-resolved tunneling processes and intrinsic magnetic properties of the molecule. Moreover, in the case of finite spin accumulation in the leads, the system exhibits the spin Seebeck effect. We demonstrate that a considerable spin Seebeck effect can develop when the molecule exhibits an easy-plane magnetic anisotropy, while the sign of the spin thermopower depends on the type and magnitude of the molecule's exchange interaction.
在本文中，我们研究了线性响应区域中强关联分子结的自旋分辨热电性质。磁性分子由一个单轨道能级建模，分子核心自旋通过交换相互作用与之相连。使用数值重整化群方法，我们分析了分子不同模型参数下（自旋）塞贝克效应、热导率和优值的行为。我们表明，热电势强烈依赖于交换相互作用的强度和类型以及分子的磁各向异性。当分子与铁磁引线耦合时，热电性质揭示了自旋分辨隧穿过程与分子固有磁性之间的相互作用。此外，在引线中存在有限自旋积累的情况下，系统表现出自旋塞贝克效应。我们证明，当分子表现出易平面磁各向异性时，会产生相当大的自旋塞贝克效应，而自旋热电势的符号取决于分子交换相互作用的类型和大小。
