Ground-state properties of electron-electron biwire systems

Abstract

The correlation between electrons in different quantum wires is expected to affect the electronic properties of quantum electron-electron biwire systems. Here, we use the variational Monte Carlo method to study the ground-state properties of parallel, infinitely thin electron-electron biwires for several electron densities (rs) and interwire separations (d). Specifically, the ground-state energy, the correlation energy, the interaction energy, the pair-correlation function (PCF), the static structure factor (SSF), and the momentum distribution (MD) function are calculated. We find that the interaction energy increases as ln(d) for d → 0 and it decreases as d −2 when d → ∞. The PCF shows oscillatory behavior at all densities considered here. As two parallel wires approach each other, interwire correlations increase while intrawire correlations decrease as evidenced by the behavior of the PCF, SSF, and MD. The system evolves from two monowires of density parameter rs to a single monowire of density parameter rs/2 as d is reduced from infinity to zero. The MD reveals Tomonaga-Luttinger (TL) liquid behavior with a power-law nature near kF even in the presence of an extra interwire interaction between the electrons in biwire systems. It is observed that when d is reduced the MD decreases for k < kF and increases for k > kF, similar to its behavior with increasing rs. The TL liquid exponent is extracted by fitting the MD data near kF, from which the TL liquid interaction parameter Kρ is calculated. The value of the TL parameter is found to be in agreement with that of a single wire for large separation between the two wires.

Study of Electron-Hole Bi-Wire System Using Quantum Monte Carlo Method

“…This is because both wires are symmetric with respect to charge and mass of mobile carriers. The inter-wire PCF indicates the strong e-h correlations due to electrostatic force of attraction between opposite charges, which is different from the case of e-e repulsive correlations [9] studied earlier. The bottom panel of Fig.…”

“…where g(x) denotes the density-weighted pair correlation function [9]. The numerical results calculated are shown below; The top panel of Fig.…”

“…al. [9] have recently studied the properties of electron-electron biwire (EEBW), whereas electron-hole systems are not explored much in the literature. The charge carriers in the wires can either be electrons in both wires or electrons in one wire and holes in another.…”

Ground-state phase diagram of the extended two-leg $t$-$J$ ladder

“…We first determine the Fermi momentum k F . Since electrons in one-dimensional systems are strongly correlated, the electron density in momentum space has no discontinuity at k F but shows a power-law behavior away from k F [85]…”

On some structural phase transitions in coupled quantum wires at finite temperature

“…The inclusion of mass-asymmetry within the qSTLS theory nicely captured Steinberg's [24] finding of Wigner crystallization. Very recently, coupled quantum wires have also been studied using Monte-Carlo (MC) simulation methods at T = 0 K with motivations other than the quantum phase transitions in these systems [26,27].…”