Spin-orbital magnetism in moiré Wigner molecules, by Ahmed Khalifa, Rokas Veitas, Francisco Machado, Shubhayu Chatterjee

SciPost Physics Home Authoring Refereeing Submit a manuscript About Spin-orbital magnetism in moiré Wigner molecules Ahmed Khalifa, Rokas Veitas, Francisco Machado, Shubhayu Chatterjee SciPost Phys. 20, 090 (2026) · published 24 March 2026 doi: 10.21468/SciPostPhys.20.3.090 pdf BiBTeX RIS Submissions/Reports Abstract The interplay of spin and orbital degrees of freedom offers a versatile playground for the realization of a variety of correlated phases of matter. However, the types of spin-orbital interactions are often limited and challenging to tune. Here, we propose and analyze a new platform for spin-orbital interactions based upon a lattice of Wigner molecules in moiré transition metal dichalcogenides (TMDs). Leveraging the spin-orbital degeneracy of the low-energy Hilbert space of each Wigner molecule, we demonstrate that TMD materials can host a general spin-orbital Hamiltonian that is tunable via the moiré superlattice spacing and dielectric environments. We study the phase diagram for this model, revealing a rich landscape of phases driven by spin-orbital interactions, ranging from ferri-electric valence bond solids to a helical spin liquid. Our work establishes moiré Wigner molecules in TMD materials as a prominent platform for correlated spin-orbital phenomena. × TY - JOURPB - SciPost FoundationDO - 10.21468/SciPostPhys.20.3.090TI - Spin-orbital magnetism in moiré Wigner moleculesPY - 2026/03/24UR - https://scipost.org/SciPostPhys.20.3.090JF - SciPost PhysicsJA - SciPost Phys.VL - 20IS - 3SP - 090A1 - Khalifa, AhmedAU - Veitas, RokasAU - Machado, FranciscoAU - Chatterjee, ShubhayuAB - The interplay of spin and orbital degrees of freedom offers a versatile playground for the realization of a variety of correlated phases of matter. However, the types of spin-orbital interactions are often limited and challenging to tune. Here, we propose and analyze a new platform for spin-orbital interactions based upon a lattice of Wigner molecules in moiré transition metal dichalcogenides (TMDs). Leveraging the spin-orbital degeneracy of the low-energy Hilbert space of each Wigner molecule, we demonstrate that TMD materials can host a general spin-orbital Hamiltonian that is tunable via the moiré superlattice spacing and dielectric environments. We study the phase diagram for this model, revealing a rich landscape of phases driven by spin-orbital interactions, ranging from ferri-electric valence bond solids to a helical spin liquid. Our work establishes moiré Wigner molecules in TMD materials as a prominent platform for correlated spin-orbital phenomena.ER - × @Article{10.21468/SciPostPhys.20.3.090, title={{Spin-orbital magnetism in moiré Wigner molecules}}, author={Ahmed Khalifa and Rokas Veitas and Francisco Machado and Shubhayu Chatterjee}, journal={SciPost Phys.}, volume={20}, pages={090}, year={2026}, publisher={SciPost}, doi={10.21468/SciPostPhys.20.3.090}, url={https://scipost.org/10.21468/SciPostPhys.20.3.090},} Ontology / Topics See full Ontology or Topics database. Frustrated magnets Spin liquids Two-dimensional systems Authors / Affiliations: mappings to Contributors and Organizations See all Organizations. 1 Ahmed Khalifa, 1 Rokas Veitas, 2 3 4 Francisco Machado, 1 Shubhayu Chatterjee 1 Carnegie Mellon University [CMU] 2 Technische Universiteit Delft / Delft University of Technology [TU Delft] 3 Harvard University 4 Harvard-Smithsonian Center for Astrophysics Funders for the research work leading to this publication Harvard University National Science Foundation [NSF]