Electron correlation and confinement effects in quasi-one-dimensional quantum wires at high density

• Main Authors: Ashokan, V. (Author), Drummond, N.D (Author), Girdhar, A. (Author), Morawetz, K. (Author), Pathak, K.N (Author)
• Format: Article
• Language: English
• Published: American Physical Society 2022
• Subjects: Approximation algorithms; Correlation energy; Electron correlation effect; First order; Ground state; Ground state properties; Momentum density; Monte Carlo methods; Nanowires; Pair correlation functions; Quasi-one dimensional; Quasi-one-dimensional; Semiconductor quantum wires; Static structure factors; Wire; Wire width
• Online Access: View Fulltext in Publisher

 We study the ground-state properties of ferromagnetic quasi-one-dimensional quantum wires using the quantum Monte Carlo (QMC) method for various wire widths b and density parameters rs. The correlation energy, pair-correlation function, static structure factor, and momentum density are calculated at high density. It is observed that the peak in the static structure factor at k=2kF grows as the wire width decreases. We obtain the Tomonaga-Luttinger liquid parameter Kρ from the momentum density. It is found that Kρ increases by about 10% between wire widths b=0.01 and b=0.5. We also obtain ground-state properties of finite-thickness wires theoretically using the first-order random phase approximation (RPA) with exchange and self-energy contributions, which is exact in the high-density limit. Analytical expressions for the static structure factor and correlation energy are derived for b≪rs<1. It is found that the correlation energy varies as b2 for b≪rs from its value for an infinitely thin wire. It is observed that the correlation energy depends significantly on the wire model used (harmonic versus cylindrical confinement). The first-order RPA expressions for the structure factor, pair-correlation function, and correlation energy are numerically evaluated for several values of b and rs≤1. These are compared with the QMC results in the range of applicability of the theory. © 2022 American Physical Society.