Designing artificial moiré van der Waals topological superconductivity

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School of Science | Doctoral thesis (article-based) | Defence date: 2024-01-26
Degree programme
103 + app. 73
Aalto University publication series DOCTORAL THESES, 225/2023
The study of topological superconductivity is a promising field in condensed matter physics that has exciting possibilities for the emergence of exotic quantum phenomena and topological quantum computing. In this thesis, we investigate various platforms for engineering topological superconductivity, focusing on the role of quasiperiodicity and van der Waals materials featuring moiré patterns. The first scheme concentrates on quasiperiodic systems and their capability to generate robust spin-triplet superconducting pairings through coexisting orders, establishing a new strategy for engineering unconventional superconductivity. In the second scheme, we focus on specific van der Waals heterostructures showing moiré patterns. We examine the role of impurities in designer topological moiré superconductors that combine van der Waals magnetic and superconducting materials, focusing on the interplay between atomic and moiré length scales within these artificial moiré systems explored with conventional tools and machine learning. In the third scheme, we focus on hybrid van der Waals heterostructures based on twisted graphene bilayers, magnets, and superconductors, establishing their potential as a versatile platform for engineering artificial topological  superconductivity. Our results showcase the potential of designer platforms, such as quasiperiodicity and moiré-patterned van der Waals materials, to harness and manipulate these intriguing quantum states. Our findings establish new strategies for developing quantum technologies based on topological superconducting quantum materials and further enrich our understanding of exotic quantum matter.
Supervising professor
Lado, Jose, Prof., Aalto University, Department of Applied Physics, Finland
Thesis advisor
Liljeroth, Peter, Prof., Aalto University, Department of Applied Physics, Finland
unconventional superconductivity, topological superconductivity, Van der waals materials
Other note
  • [Publication 1]: Maryam Khosravian and Jose L. Lado. Quasiperiodic criticality and spin-triplet superconductivity in superconductor-antiferromagnet moiré patterns. Physical Review Research, 3, 013262, March 2021.
    DOI: 10.1103/PhysRevResearch.3.013262 View at publisher
  • [Publication 2]: Maryam Khosravian and Jose L. Lado. Impurity-induced excitations in a topological two-dimensional ferromagnet/superconductor van der Waals moiré heterostructure. Physical Review Materials, 6, 094010, September 2022.
    DOI: 10.1103/PhysRevMaterials.6.094010 View at publisher
  • [Publication 3]: Guangze Chen, Maryam Khosravian, Jose L. Lado, Aline Ramires. Designing spin-textured flat bands in twisted graphene multilayers via helimagnet encapsulation. 2D Materials, 9, 024002, February 2022.
    DOI: 10.1088/2053-1583/ac4af8 View at publisher
  • [Publication 4]: Maryam Khosravian, Leni Bascones, Jose L. Lado. Moiré-enabled artificial topological superconductivity in twisted bilayer graphene. Submitted to 2D Materials, July 2023.
    DOI: 10.48550/arXiv.2307.04605 View at publisher
  • [Publication 5]: Maryam Khosravian, Rouven Koch, Jose L. Lado. Hamiltonian learning with real-space impurity tomography in topological moiré superconductors. Submitted to Journal of Physics: Materials, August 2023.
    DOI: 10.48550/arXiv.2308.11400 View at publisher