Unified Variational Approach Description of Ground-State Phases of the Two-Dimensional Electron Gas
Published in Phys. Rev. Lett., 2024
Recommended citation: C. Smith, Y. Chen, R. Levy, Y. Yang, M. A. Morales, S. Zhang, "Unified Variational Approach Description of Ground-State Phases of the Two-Dimensional Electron Gas, " Phys. Rev. Lett. 133, 266504 (2024). https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.133.266504
The two-dimensional electron gas (2DEG) is a fundamental model, which is drawing increasing interest because of recent advances in experimental and theoretical studies of 2D materials. Current understanding of the ground state of the 2DEG relies on quantum Monte Carlo calculations, based on variational comparisons of different Ansätze for different phases. We use a single variational ansatz, a general backflow-type wave function using a message-passing neural quantum state architecture, for a unified description across the entire density range. The variational optimization consistently leads to lower ground-state energies than previous best results. Transition into a Wigner crystal (WC) phase occurs automatically at 𝑟𝑠=37±1, a density lower than currently believed. Between the liquid and WC phases, the same ansatz and variational search strongly suggest the existence of intermediate states in a broad range of densities, with enhanced short-range nematic spin correlations.