We investigate the effect of many-body correlations on the ground-state properties of two coupled charged Bose quantum wires. The intrawire and interwire correlations are treated on the same footing within the self-consistent mean-field theory of Singwi, Tosi, Land and Sjölander. Static properties, viz. , pair-correlation functions, local-field correction factors, screened interactions and susceptibilities, are calculated for a range of wire spacings d , wire radii , and boson density parameters . We find that the qualitative dependence of intrawire correlations on and remains the same as found for an isolated wire, except that they become slightly weaker with the decreasing spacing d . The interwire correlations, on the other hand, depend strongly on d and are found to grow in magnitude with decreasing d . Further, we find no evidence for the existence of a charge-density-wave ground state in the density range investigated, , in the close proximity of wires. A comparison with the similar studies on the coupled electron quantum wires reveals that the charge-density-wave instability observed there may be an artifact of the neglect of interwire correlation effects.
Abstract In this work, the computational method of Variational Monte Carlo is used to study the ground state properties of electron-hole (e-h) bi-wire systems. We have calculated the pair correlation function and static structure factor of a coupled infinitely thin e-h wire system of electronic density (rs= 1) and inter-wire distance (d = 1). The numerical calculation is carried out using the many-body trial wave function of the Slater-Jastrow backflow type. It is observed that the inter-wire correlations become quite important in the case of the mass-symmetric electron-hole bi-wire system due to the coulomb attractive nature of the bi-wire system.
Abstract We investigate the ground-state properties of an electron-phonon (e-ph) coupled quantum wire in which the effect of coupling between longitudinal optical (LO) phonons and the wire electrons is considered, in addition to the conventional electron-electron (e-e) interactions. The e-ph coupling is included through the Fröhlich interaction potential and the dynamics of electron correlations using the quantum (dynamic) version of self-consistent mean-field approximation of Singwi et al (the qSTLS approach). Numerical results for static structure factor, pair-correlation function and static density susceptibility are presented over a wide range of electron number density parameter r s . We find that the electrons undergo Wigner crystallization at a critical electron density parameter r s c owing to the dynamics of severely correlated electrons. Notably at a fixed wire width, the inclusion of e-ph coupling tends to increase the value of r s c significantly in comparison to a situation in which only the e-e interactions are considered. Besides this, we compute the plasmon-phonon (pl-ph) coupled modes and the energy contribution of e-ph interactions ( E e − ph ) to the ground-state energy of the quantum wire, also known as polaronic energy. We find that pl-ph coupled modes resonantly split into two branches, and ∣ E e − ph ∣ monotonically increases with rise in r s then becomes almost constant as r s → r s c . Wherever interesting, we compare our results with the static STLS theory and the lattice regularized diffusion Monte Carlo (LRDMC) simulation data of Casula et al .
The dynamics of semiconductor quantum wires and wells that are coupled to a single-mode quantum field are analyzed. Within a two-band tight-binding model the Coulomb interaction between electrons and holes is included on a microscopic basis and the light-matter interaction is quantized. The dynamics of the system is described by equations of motion for the relevant set of expectation values of the coupled electronic-photonic system. Starting from the initial condition of a single photon occupying the field mode, we study the dynamics of the mean photon number. To analyze effects arising from the many-body Coulomb interaction, we use an exact truncation of the electronic hierarchy problem by employing the fact that N photons cannot excite more than N electron-hole pairs. We compare Rabi oscillations with and without Coulomb interaction for different excitation conditions. When the quantum field mode is initially occupied by two photons, two interacting electron-hole pairs, i.e., biexcitons, can be generated which characteristically modify the dynamics. Within a consistent and fully-quantized approach we show consequences of biexcitonic many-body correlations that are coupled to a quantum field and discuss the obtained dynamics.
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 $d\ensuremath{\rightarrow}0$ and it decreases as ${d}^{\ensuremath{-}2}$ when $d\ensuremath{\rightarrow}\ensuremath{\infty}$. 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 ${K}_{\ensuremath{\rho}}$ 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.