Ioffe Institute of the Russian Academy of Sciences , 194021 St. Petersburg, Russia.
Lappeenranta University of Technology , P.O. Box 20, 53851 Lappeenranta, Finland.
ACS Nano. 2017 Jul 25;11(7):6868-6880. doi: 10.1021/acsnano.7b02014. Epub 2017 Jun 21.
We present experimental results and a theoretical model for the gate-controlled spin-valve effect in carbon nanotubes with side-attached single-molecule magnets TbPc (Terbium(III) bis-phthalocyanine). These structures show a giant magnetoresistance up to 1000% in experiments on single-wall nanotubes that are tunnel-coupled to the leads. The proposed theoretical model combines the spin-dependent Fano effect with Coulomb blockade and predicts a spin-spin interaction between the TbPc molecules, mediated by conducting electrons via the charging effect. This gate-tuned interaction is responsible for the stable magnetic ordering of the inner spins of the molecules in the absence of magnetic field. In the case of antiferromagnetic arrangement, electrons with either spin experience the scattering by the molecules, which results in blocking the linear transport. In strong magnetic fields, the Zeeman energy exceeds the effective antiferromagnetic coupling and one species of electrons is not scattered by molecules, which leads to a much lower total resistance at the resonant values of gate voltage, and hence to a supramolecular spin-valve effect.
我们提出了实验结果和理论模型，用于研究侧附单分子磁体 TbPc（三价铽双酞菁）的碳纳米管中的栅控自旋阀效应。这些结构在单壁碳纳米管的实验中表现出高达 1000%的巨磁电阻，这些碳纳米管与引线通过隧道耦合。所提出的理论模型将自旋相关的 Fano 效应与库仑阻塞相结合，并预测了通过电荷效应通过传导电子介导的 TbPc 分子之间的自旋-自旋相互作用。这种栅极调谐的相互作用是在没有磁场的情况下分子内自旋稳定磁序的原因。在反铁磁排列的情况下，具有任一自旋的电子都会经历分子的散射，从而阻止线性输运。在强磁场中，塞曼能量超过有效反铁磁耦合，一种电子不会被分子散射，这导致在栅极电压的共振值处总电阻低得多，从而导致超分子自旋阀效应。
