Quantum Monte Carlo calculation of the energy band and quasiparticle effective mass of the two-dimensional Fermi fluid

TL;DR

This study employs diffusion quantum Monte Carlo to compute the energy band and quasiparticle effective mass of a two-dimensional electron gas, revealing density-dependent mass variations consistent with experimental findings.

Contribution

First application of diffusion quantum Monte Carlo to determine the energy band and effective mass in 2D electron gases, providing insights into density effects and experimental agreement.

Findings

Effective mass increases at lower densities in paramagnetic HEG.

Effective mass decreases at lower densities in ferromagnetic HEG.

Results align with recent experimental observations.

Abstract

We have used the diffusion quantum Monte Carlo method to calculate the energy band of the two-dimensional homogeneous electron gas (HEG), and hence we have obtained the quasiparticle effective mass and the occupied bandwidth. We find that the effective mass in the paramagnetic HEG increases significantly when the density is lowered, whereas it decreases in the fully ferromagnetic HEG. Our calculations therefore support the conclusions of recent experimental studies [Y.-W. Tan et al., Phys. Rev. Lett. 94, 016405 (2005); M. Padmanabhan et al., Phys. Rev. Lett. 101, 026402 (2008); T. Gokmen et al., Phys. Rev. B 79, 195311 (2009)]. We compare our calculated effective masses with other theoretical results and experimental measurements in the literature.