DFG-RSF: Impact of topology on electronic properties of ordered materials
Experimental Condensed Matter Physics
Final Report Abstract
The problem of novel material engineering is highly topical due to its potential impact on environment, natural resources saving, progress in telecommunications, and life quality, in total. In spite of almost 30 years history of cuprate HTS, the phase diagram and properties of the layered HTS materials are still actual. At the moment of application there were highly debated effects of the spin and orbital fluctuations, spin and charge ordering, many body effects (in the vicinity of the Lifshitz topological transition), and topology of the surface states (flat bands). Clearly, the role of potentially favorable factors for HTS had to be clarified for the purposeful searching and engineering novel HTS materials. The current project aimed at theoretical development and experimental implementation of the superconductors engineering based on layered materials (both pnictide, and dichalcogenide-based), studying their properties in the vicinity of QCP, clarifying the role of the interplay of magnetic ions ordering, charge ordering and SC pairing. The main idea of the project consisted in studying and use of the flat band materials, both topologically trivial, and non-trivial. The former results in the enhanced contribution of the manybody condensation energy to the SC gap due to the proximity to the Lifshitz transition, the latter – due to the non-trivial topology (Weyl semimetals). The flat band conditions in the topologically non-trivial materials were expected to be tuned using the band engineering methods (hydrostatic pressure, chemical and electric doping). All the goals of this project were achieved thanks to the collaboration of Moscow and Dresden groups.
Publications
- Fate of interaction-driven topological insulators under disorder. Phys. Rev B 96, 201104 (2017)
Wang, Jing; Ortix, Carmine; van den Brink, Jeroen; et al.
(See online at https://doi.org/10.1103/PhysRevB.96.201104) - Selective mass enhancement close to the quantum critical point in BaFe2(As1−x P x )2 . Sci Rep 7, 4589 (2017)
Grinenko, V., Iida, K., Kurth, F. et al.
(See online at https://doi.org/10.1038/s41598-017-04724-3) - Topological Lifshitz transitions Low Temperature Physics, 43, 57 (2017)
Volovik G. E.
(See online at https://doi.org/10.1063/1.4974185) - Thickness dependent electronic structure of exfoliated mono- and few-layer 1T '-MoTe2. Phys Rev Mat 2, 104004 (2018)
Pawlik, AS ; Aswartham, S; Morozov, I; Knupfer, M ; Buchner, B ; Efremov, DV; Koitzsch, A
(See online at https://doi.org/10.1103/PhysRevMaterials.2.104004) - Topology of a 3He-A Film on a Corrugated Graphene Substrate. JETP Lett. 107, 115 (2018)
Volovik, G. E.
- Two-dimensional semimetal in HgTe quantum well under hydrostatic pressure, Phys. Rev. B 98, 155437 (2018)
V. A. Prudkoglyad, E. B. Olshanetsky, Z. D. Kvon, V. M. Pudalov, N. N. Mikhailov, and S. A. Dvoretsky
(See online at https://doi.org/10.1103/PhysRevB.98.155437) - "Topological Insulator: Surface Localized States", Journal of Superconductivity and Novel Magnetism 32, 1327(2019)
Yu. N. Ovchinnikov
(See online at https://doi.org/10.1007/s10948-018-4827-0) - Absence of Dirac fermions in layered BaZnBi2, Phys. Rev. Materials 3, 024202 (2019)
Thirupathaiah, S., Efremov, D., Kushnirenko, Y., Haubold, E., Kim, T. K., Pienning, B. R., Morozov, I., Aswartham, S., Buechner, B., Borisenko, S. V.
(See online at https://doi.org/10.1103/PhysRevMaterials.3.024202) - Singular ground state of multiband inhomogeneous superconductors, Phys. Rev. B 99, 224508 (2019)
Ovchinnikov, Yu N., Efremov, D. V.
(See online at https://doi.org/10.1103/PhysRevB.99.224508)
