Dissertation: Spin Physics of Novel Chiral Electron Gases, FAU Erlangen-Nürnberg, 2018. View

Description: In my PhD thesis I studied the spin structure and magnetic interactions in novel materials. The main job was to solve the Schrödinger equation for novel many body systems and to derive from these solutions quantities like the spin structure and the interaction energy for the RKKY (Ruderman-Kittel-Kasuya-Yosida) interaction. The RKKY interaction is a special type of magnetic interaction which is mediated by the electron gas. In former works people found that the RKKY interaction is on the surface of copper responsible for a spin coupling which oscillates as a function of the impurity separation. In my work it turned out that the RKKY interaction depends in the carbon allotrope graphene heavily on the temperature and can be controlled by an external electric field which is applied between the two layers of a bilayer system. Another important finding of my work is the spin texture of a topological insulator of the SnTe class. The surface state spin texture can be tuned as a function of the band bending from elliptic through linear to hyperbolic.

More publications:

1. Tuning topological surface magnetism by bulk alloying, Aug. 2019, Klier, N. und Sharma, S. und Rost, F. und Pankratov, O. und Shallcross, S., Phys. Rev. B 100, https://journals.aps.org/prb/abstract/10.1103/PhysRevB.100.075130.

2. Bulk physics entwined with a topological surface state, Feb. 2017, Klier, N. und Sharma, S. und Pankratov, O. und Shallcross, S., eprint arXiv:1702.08784, https://arxiv.org/abs/1702.08784.

3. Electrical control of the RKKY interaction in bilayer graphene, Nov. 2016, Klier, N. und Sharma, S. und Pankratov, O. und Shallcross, S., Phys. Rev. B 94, 205436, https://journals.aps.org/prb/abstract/10.1103/PhysRevB.94.205436.

4. Ruderman-Kittel-Kasuya-Yosida interaction at finite temperature: Graphene and bilayer graphene, Nov. 2015, Klier, N. und Shallcross, S. und Sharma, S. und Pankratov, O., Phys. Rev. B 92, 205414, https://journals.aps.org/prb/abstract/10.1103/PhysRevB.92.205414.

5. Asymptotic discontinuities in the RKKY interaction in the graphene Bernal bilayer, Dez. 2014, Klier, N. und Shallcross, S. und Pankratov, O., Phys. Rev. B 90, 245118, https://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.245118.