Collective modes and Raman scattering in one dimensional electron systems

Abstract

In this paper, we review recent development in the theory of resonant inelastic light (Raman) scattering in one-dimensional electron systems. The particular systems we have in mind are electron doped GaAs based semiconductor quantum wire nanostructures, although the theory can be easily modified to apply to other one-dimensional systems. We compare the traditional conduction-band-based non-resonant theories with the full resonant theories including the effects of interband transitions. We find that resonance is essential in explaining the experimental data in which the single particle excitations have finite spectral weights comparable to the collective charge density excitations. Using several different theoretical models (Fermi liquid model, Luttinger liquid model, and Hubbard model) and reasonable approximations, we further demonstrate that the ubiquitously observed strong single particle excitations in the experimental Raman spectra cannot be explained by the spinless multi-spinon excitations in the Luttinger liquid description. The observability of distinct Luttinger liquid features in the Raman scattering spectroscopy is critically discussed. q

Electronic Raman scattering in unconventional density waves

“…[32]. The pole of the screened density correlator leads to the plasmon mode [38], which however does not affect the low energy behavior. Furthermore, the nondiagonal χ γ1 term is expressed as…”

Coherent Quantum Optics Phenomena in Carbon Low-Dimensional Systems

“…where ξ (1,2) |l−j| are the energies, characterising intrachain (l = j) and interchain (l = j) σ-polaron-σ-polaron interaction for the excited (ξ (1) ) and ground (ξ (2) ) states of j-th chain, |b mj , |a mj are ground and excited states correspondingly of m-th σ-polaron of j-th chain. Matrix [e 1 ] j in (6) to ( 9) is j-th power of the circulant matrix [e 1 ], which is the following…”

“…Right hand side expression in ( 31) is vector product of vector operators. It can be calculated by using of known expression (39) with additional coefficient 1 2 the only, which is appeared, since…”

“…Let us also remark, that in all theoretical and experimental studies of the matter systems by means of stationary optical-and radio spectroscopy methods EM-field is considered the only classically. For example, in relatively recent work [1] the review of development in the theory of resonant Raman scattering (RS) in 1D electron systems is given by using several different quantum theoretical models of the matter subsystem -Fermi liquid model, Luttinger liquid model and Hubbard model, however by classical description of EM-field.…”

The effects of the plasmon-LO phonon interaction on the critical densities of RPA approach in a quasi-one-dimensional system

“…The many-body effects of a quasi-one-dimensional (Q1D) electron gas present in a quantum well wire (QWW) structure have motivated a significant number of works [7][8][9][10][11][12]. The most common method used in theoretical works has been the random-phase approximation (RPA).…”