I posted a new paper on arXiv! Titled Ground state phases of the two-dimension electron gas with a unified variational approach, a group of us at Flatiron CCQ including two great graduate student predoctoral researchers developed a new package for performing variational Monte Carlo (VMC) in real space simulating the uniform electron gas in 2D (also known as Jellium). Using a message-passing interface based on [1] but with multiple planewaves (MPs), we find a new location for the liquid-Wigner crystal transition at rs = 37+/-1 and find nematic spin correlations between the two phases. Hope you take a look!
Abstract
Conor Smith, Yixiao Chen, Ryan Levy, Yubo Yang, Miguel A. Morales, Shiwei Zhang
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 ansatze 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.
[1] see Pescia, et al arxiv:2305.07240 Phys. Rev. B 110, 035108 (2024)