YRLG Workshop: Correlation and Topology in magnetic materials, July 16th - 18th 2024
Subhradeep Misra
Two-dimensional van der Waals materials exhibiting moiré physics provide a unique platform for studies of correlated many-body effects, implementing the two-dimensional Fermi-Hubbard model on a triangular spin-charge lattice. In this work, we demonstrate the realization of a staggered bilayer triangular lattice of electrons in an antiparallel MoSe2/WS2 heterostructure. The bilayer lattice emerges due to strong electron confinement in the moiré potential minima and the near-resonant alignment of conduction band edges in MoSe2 and WS2. As a result, charge filling proceeds layer-by-layer, with the first and second electron per moiré unit cell consecutively occupying first the MoSe2 and then the WS2 layer. We describe the observed charging sequence by an electrostatic model and provide experimental evidence of antiferromagnetic spin correlations on the vertically offset and staggered bilayer lattice, yielding absolute exciton Landé factors as high as 600 at the lowest temperatures. The bilayer character of the implemented spin-charge lattice allows for the electrical tunability of RKKY-type magnetism. It establishes antiparallel MoSe2/WS2 heterostructures as a valuable system for quantum simulation of strongly coupled bilayer Hubbard model physics, enabling future studies of exotic magnetic phases in frustrated lattices.