DQMP Forum - Kagome Chiral Spin Liquid in Transition Metal Dichalcogenide Moiré Bilayers - Disorder Dynamics in Driven Amorphous Materials

09.05.2023 13:00 – 14:00

Kagome Chiral Spin Liquid in Transition Metal Dichalcogenide Moiré Bilayers
Johannes Motruk (Group of prof. Abanin)

Charge carriers in fractionally filled flat bands of transition metal dichalcogenide (TMD) moir´e bilayers can form generalized Wigner crystals. At n=3/4 filling, such a system develops charge order in a kagome pattern resulting in localized spins on this lattice geometry. Starting from an extended Hubbard model description, we derive an effective spin model on the kagome lattice and find that its further neighbor spin interactions can be much less suppressed than the corresponding electron hopping strength. Using density matrix renormalization group simulations, we study its phase diagram and, for realistic model parameters relevant for WSe2/WS2, we show that this material can realize the exotic chiral spin liquid phase and the highly debated kagome spin liquid.
Our work thus demonstrates that the frustration and strong inter-actions present in TMD heterobilayers provide a novel experimental realization of kagome spin models, representing an exciting platform to study spin liquid physics.


Disorder Dynamics in Driven Amorphous Materials
Elisabeth Agoritsas (group of prof. Giamarchi)

Disorder is ubiquitous in physical systems, and can radically alter their physical properties compared to their pure counterparts. For instance, amorphous materials such as emulsions, foams, metallic glasses or biological tissues are all structurally disordered, and this has key implications for their rheological, mechanical or transport properties. Nevertheless, theoretical descriptions of such driven amorphous materials remain challenging, despite decades of extensive analytical and computational studies. Here I will introduce the so-called elasto-plastic models, which are phenomenological models at a mesoscopic scale for amorphous materials, based on an ad hoc effective dynamics of the local shear stress. I will in particular discuss which theoretical insights these models can provide on the dynamics of structural disorder and its related properties.

Lieu

Bâtiment: Ecole de Physique

Auditoire Stückelberg

entrée libre