Designing exotic phases of matter with magnetic van der Waals materials

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School of Science | Doctoral thesis (article-based) | Defence date: 2023-06-26
Degree programme
138 + app. 184
Aalto University publication series DOCTORAL THESES, 84/2023
Magnetic van der Waals materials have recently emerged as a realization of quantum magnetism in two dimensions. They host a variety of phases including ferromagnets, anti-ferromagnets, helimagnets, and quantum spin liquids. The 2D nature of these materials makes them versatile platforms for quantum engineering. In this thesis, we explore via theoretical techniques how different quantum engineering methods allow to design and reveal exotic phases of matter in magnetic van der Waals materials. In particular, we will present three schemes. The first scheme focuses on external engineering on a 2D magnet to promote and identify the quantum spin liquid phase. The second scheme focuses on designing helical electronic states and heavy fermions via proximity to 2D magnets. The third scheme focuses on the utilization of the coupling of quantum magnets to the environment to design non-Hermitian many-body topological phases of matter. Our results put forward magnetic van der Waals materials as a versatile platform for engineering exotic phases of matter.
Supervising professor
Lado, Jose L., Prof., Aalto University, Department of Applied Physics, Finland
magnetic van der Waals materials, quantum spin liquids, helical states, heavy-fermions, non-Hermitian physics
Other note
  • [Publication 1]: Guangze Chen, Jose L. Lado. Impurity-induced resonant spinon zero modes in Dirac quantum spin liquids. Physical Review Research, 2, 033466, September 2020.
    Full text in Acris/Aaltodoc:
    DOI: 10.1103/PhysRevResearch.2.033466 View at publisher
  • [Publication 2]: Guangze Chen, Jose L. Lado. Tunable moire spinons in magnetically encapsulated twisted van der Waals quantum spin liquids. Physical Review Research, 3, 033276, September 2021.
    Full text in Acris/Aaltodoc:
    DOI: 10.1103/PhysRevResearch.3.033276 View at publisher
  • [Publication 3]: Guangze Chen, Malte Rösner, Jose L. Lado. Controlling magnetic frustration in 1T-TaS2 via Coulomb engineered long-range interactions. Journal of Physics: Condensed Matter, 34, 485805, October 2022.
    Full text in Acris/Aaltodoc:
    DOI: 10.1088/1361-648X/ac9812 View at publisher
  • [Publication 4]: 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.
    Full text in Acris/Aaltodoc:
    DOI: 10.1088/2053-1583/ac4af8 View at publisher
  • [Publication 5]: Viliam Vaňo, Mohammad Amini, Somesh C. Ganguli, Guangze Chen, Jose L. Lado, Shawulienu Kezilebieke and Peter Liljeroth. Artificial heavy fermions in a van der Waals heterostructure. Nature, 599, 582–586, November 2021.
    DOI: 10.1038/s41586-021-04021-0 View at publisher
  • [Publication 6]: Guangze Chen, Fei Song, Jose L. Lado. Topological spin excitations in non-Hermitian spin chains with a generalized kernel polynomial algorithm. Physical Review Letters, 130, 100401, March 2023.
    Full text in Acris/Aaltodoc:
    DOI: 10.1103/PhysRevLett.130.100401 View at publisher