Nitin Kaushal – Quantum Matter Institute

Title: Realization of magnetically frustrated Wigner crystals and a novel multiorbital model in transition metal dichalcogenide based moiré materials

Abstract: Moiré materials constructed using the transition metal dichalcogenide (TMD) bilayers have been used to simulate the Hubbard model with long range Coulomb interactions procuring the lattice Wigner crystal states at fractional fillings like n=2/3, 1/2, and 1/3. We study the gamma-valley TMD homobilayers which can give rise to the effective moire honeycomb lattices, as shown by recent ab-initio studies. We discuss the effect of Coulomb interactions in these homobilayers unveiling the plethora of frustrated magnetic states on Wigner crystals at various fractional fillings, which suggests the latent potential of these materials to realize quantum spin liquids. Moreover, by performing Wannierization of the moiré bands we show that these materials can realize a more general moire Kanamori-Hubbard model, opening an avenue for physics beyond the extensively studied multiorbital Hubbard model.

Speaker Bio: Dr. Nitin Kaushal is a postdoctoral fellow at the Quantum Matter Institute working with Professor Marcel Franz’s group. Prior to joining UBC, he worked as a postdoctoral researcher at the Oak Ridge National Laboratory (2020-2023. Nitin completed his PhD at the University of Tennessee in 2020, under the guidance of Prof. Elbio Dagotto. During his Ph.D., he investigated the effects of atomic spin-orbit coupling on the multi-orbital Hubbard models. In recent years, Nitin’s research has been centered on moiré materials.