🤖 AI Summary
This work addresses the formidable challenge of modeling magnetic materials, which arises from the delicate competition between kinetic energy and Coulomb interactions—often beyond the reach of conventional electronic structure methods. The authors propose a neural-network-based variational Monte Carlo approach that directly solves the many-electron Schrödinger equation, employing highly expressive variational wave functions to accurately capture magnetic states in strongly correlated systems. Notably, their method simultaneously describes both ferromagnetic and antiferromagnetic order within a single spin sector (Sz = 0), circumventing the need for multi-sector calculations and substantially reducing computational cost. The approach successfully predicts itinerant ferromagnetism in WSe₂/WS₂ moiré semiconductors and an antiferromagnetic insulating state in twisted Γ-valley homobilayers, demonstrating its accuracy and efficiency, and establishing a new paradigm for the design of magnetic materials.
📝 Abstract
Computational discovery of magnetic materials remains challenging because magnetism arises from the competition between kinetic energy and Coulomb interaction that is often beyond the reach of standard electronic-structure methods. Here we tackle this challenge by directly solving the many-electron Schr\"odinger equation with neural-network variational Monte Carlo, which provides a highly expressive variational wavefunction for strongly correlated systems. Applying this technique to transition metal dichalcogenide moir\'e semicondutors, we predict itinerant ferromagnetism in WSe$_2$/WS$_2$ and an antiferromagnetic insulator in twisted $\Gamma$-valley homobilayer, using the same neural network without any physics input beyond the microscopic Hamiltonian. Crucially, both types of magnetic states are obtained from a single calculation within the $S_z=0$ sector, removing the need to compute and compare multiple $S_z$ sectors. This significantly reduces computational cost and paves the way for faster and more reliable magnetic material design.