Inelastic electron and Raman scattering from the collective excitations in quantum wires: Zero magnetic field

TL;DR

This paper investigates inelastic electron and Raman scattering in quantum wires, analyzing electronic excitations and dielectric properties within a Fermi liquid framework at zero magnetic field.

Contribution

It provides a systematic theoretical analysis of inelastic scattering processes in quantum wires using the random-phase approximation, emphasizing dielectric functions and collective excitations.

Findings

Derivation of the generalized nonlocal, dynamic dielectric function.

Analysis of inelastic electron and light scattering spectra.

Insights into collective excitations in quantum wires.

Abstract

The nanofabrication technology has taught us that an $m$-dimensional confining potential imposed upon an $n$-dimensional electron gas paves the way to a quasi-($n-m$)-dimensional electron gas, with $m \le n$ and $1\le n, m \le 3$. This is the road to the (semiconducting) quasi-$n$ dimensional electron gas systems we have been happily traversing on now for almost three decades. Achieving quasi-one dimensional electron gas (Q-1DEG) [or quantum wire(s) for more practical purposes] led us to some mixed moments in this journey: while the reduced phase space for the scattering led us believe in the route to the faster electron devices, the proximity to the 1D systems left us in the dilemma of describing it as a Fermi liquid or as a Luttinger liquid. No one had ever suspected the potential of the former, but it took quite a while for some to convince the others on the latter. A realistic Q-1DEG system at the low temperatures is best describable as a Fermi liquid rather than as a Luttinger liquid. In the language of condensed matter physics, a critical scrutiny of Q-1DEG systems has provided us with a host of exotic (electronic, optical, and transport) phenomena revealing their unparallel behavior characteristics unseen in their higher or lower dimensional counterparts. Here, we embark on the systematic investigation of the inelastic electron scattering (IES) and of inelastic light scattering (ILS) from the elementary electronic excitations in quantum wires in the absence of an applied magnetic field. To that end, we begin with the Kubo's correlation functions to derive the generalized nonlocal, dynamic dielectric function, the inverse dielectric function, and the Dyson equation for the dynamic screened potential in the framework of Bohm-Pines' full and famous random-phase approximation...