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arXiv:1306.3781

Charge and spin density waves: Quasi one dimension to two dimension

Urbashi Satpathi, Sumit Ghosh, Alak K. Ray, P. Singha Deo

Published Jun 17, 2013• 0 citations
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Abstract

Possibility of electronic charge and spin separation leading to charge density wave and spin density wave is well established in one dimensional systems in presence and absence of Coulomb interaction. We start from quasi one dimension and show the possibility of such a transition in quasi one dimension as well as in two dimension by going to a regime where it can be shown for free electrons that just interact via Fermi statistics. Since Coulomb interaction can only facilitate the phenomenon, the purpose of our work is to show the phenomena unambiguously in the limit when Coulomb interaction can be ignored. Finally we also comment on dimensions greater than two and inclusion of Coulomb interactions.

DOI
10.48550/arxiv.1306.3781

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Possibility of electronic charge and spin separation leading to charge density wave and spin density wave is well established in one dimensional systems in presence and absence of Coulomb interaction. We start from quasi one dimension and show the possibility of such a transition in quasi one dimension as well as in two dimension by going to a regime where it can be shown for free electrons that just interact via Fermi statistics. Since Coulomb interaction can only facilitate the phenomenon, the purpose of our work is to show the phenomena unambiguously in the limit when Coulomb interaction can be ignored. Finally we also comment on dimensions greater than two and inclusion of Coulomb interactions.
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A one-dimensional gas of electrons interacting with long-range Coulomb forces [V(r)\ensuremath{\approxeq}1/r] is investigated. The excitation spectrum consists of separate collective charge and spin modes. For arbitrarily weak Coulomb repulsion density correlations at wave vector 4kF{\mathit{k}}_{\mathit{F}}kF​ decay extremely slowly and are best described as those of a one-dimensional Wigner crystal. Pinning of the Wigner crystal then leads to the nonlinear transport properties characteristic of charge density waves. The results allow a consistent interpretation of the plasmon and spin excitations observed in one-dimensional semiconductor structures, and suggest an interpretation of some of the observed features in terms of ``spinons.''
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