Raul Perea Causin
Contact
Name and title: Raul Perea Causin
ORCID0000-0002-2229-0147 Länk till annan webbplats.
Workplace: Department of Physics Länk till annan webbplats.
Visiting address Roslagstullsbacken 21
Postal address Fysikum106 91 Stockholm
About me
I am a postdoctoral researcher in the Quantum and Complex Systems group, where I study novel quantum phases of matter arising from the interplay of strong interactions and topology. My research aims to understand and predict new forms of topological order with a main focus on moiré materials, which provide an experimentally accessible platform for realizing strongly correlated quantum states.
Recently, I have explored unconventional topological phases including Hall crystals, non-Abelian anyons with Fibonacci statistics, and topological order without band topology. A central focus of my current work is bosonic topological order enabled by long-lived excitons. In particular, I have shown that exciton fractional Chern insulators can be remarkably robust, and that excitonic systems may even host non-Abelian phases.
My research contributes to the fundamental understanding of quantum many-body physics in engineered materials and helps establish realistic pathways toward realizing and controlling exotic topological states, with potential relevance for future quantum technologies.
I obtained my PhD in 2023 at Chalmers University of Technology, where I developed microscopic models of excitons and charge complexes in atomically thin semiconductors, work that was recognized with the Department of Physics and Graphene Center at Chalmers best PhD thesis awards.
My research focuses on understanding and predicting emergent quantum phases of matter that arise from the interplay of strong interactions and topology. I am particularly interested in topological order in moiré materials, where nearly-flat bands with non-trivial quantum geometry provide a powerful platform for realizing exotic many-body physics. My research interests also include excitonic phenomena in two-dimensional semiconductors.
Topological order and fractional Chern insulators
A central direction of my research is the study of fractional Chern insulators and related topological phases in moiré heterostructures. These systems enable the realization of strongly correlated topological states without external magnetic fields, such as the fractional quantum anomalous Hall effect. My recent work has provided deep insights on the stabilization of quantum anomalous Hall crystals, the emergence of topological order in topologically trivial bands, and the potential realization of non-Abelian phases hosting Fibonacci anyons.
Excitons and bosonic quantum matter
Excitons in atomically thin semiconductors provide a unique solid-state platform for realizing bosonic quantum phases of matter. I have developed models to describe excitonic complexes in two-dimensional semiconductors, with the goal of understanding and predicting relevant experimental signatures. Recently, I have demonstrated the high stability of exciton fractional Chern insulators in moiré heterostructures and established excitonic systems as a promising platform for realizing (Abelian and non-Abelian) bosonic topological order.
My research has resulted in about 40 peer-reviewed publications in leading journals in condensed matter physics and quantum materials.
A full and up-to-date publication list is available on my Google Scholar profile:
https://scholar.google.com/citations?user=ezVIhLAAAAAJ
Selected publications:
Exciton fractional Chern insulators in moiré heterostructures
R. Perea-Causin, H. Liu, E. J. Bergholtz
Physical Review Research 7, L042033 (2025)
https://doi.org/10.1103/55zv-s9xv
Quantum anomalous Hall crystals in moiré bands with higher Chern number
R. Perea-Causin, H. Liu, and E. J. Bergholtz
Nature Communications 16, 6875 (2025)
https://doi.org/10.1038/s41467-025-62224-9
Parafermions in moiré minibands
H. Liu, R. Perea-Causin, and E. J. Bergholtz
Nature Communications 16, 1770 (2025)
https://doi.org/10.1038/s41467-025-57035-x
Trion photoluminescence and trion stability in atomically thin semiconductors
R. Perea-Causin, S. Brem, O. Schmidt, and E. Malic
Physical Review Letters 132, 036903 (2024)
https://doi.org/10.1103/PhysRevLett.132.036903
Ultrafast switching of trion emitters in 2D materials
T. Venanzi, M. Cuccu, R. Perea-Causin, et al.
Nature Photonics 18, 1344 (2024)
https://doi.org/10.1038/s41566-024-01512-0
Electrically tunable layer-hybridized trions in doped WSe₂ bilayers
R. Perea-Causin, S. Brem, F. Buchner, et al.
Nature Communications 15, 6713 (2024)
https://doi.org/10.1038/s41467-024-50834-8