Multi-Fluid Hydrodynamics in Charge Density Waves with Collective, Electronic, and Solitonic Densities and Currents
- PDF / 1,435,804 Bytes
- 10 Pages / 612 x 792 pts (letter) Page_size
- 16 Downloads / 230 Views
ontribution for the JETP special issue in honor of I. M. Khalatnikov’s 100th anniversary
Multi-Fluid Hydrodynamics in Charge Density Waves with Collective, Electronic, and Solitonic Densities and Currents S. Brazovskiia,* and N. Kirovab a LPTMS, b
UMR 8626, CNRS & Université Paris-sud, Univ. Paris-Saclay, Bat. 510, Orsay, cedex, 91405 France LPS, UMR 8502, CNRS & Université Paris-sud, Univ. Paris-Saclay, Bat. 510, Orsay, cedex, 91405 France *e-mail: [email protected] Received May 3, 2019; revised May 3, 2019; accepted June 6, 2019
Abstract—We present a general scheme to approach the space-time evolution of deformations, currents, and the electric field in charge density waves related to appearance of intrinsic topological defects: dislocations, their loops or pairs, and solitons. We derive general equations for the multi-fluid hydrodynamics taking into account the collective mode, electric field, normal electrons, and the intrinsic defects. These equations may allow to study the transformation of injected carriers from normal electrons to new periods of the charge density wave, the collective motion in constrained geometry, and the plastic states and flows. As an application, we present analytical and numerical solutions for distributions of fields around an isolated dislocation line in the regime of nonlinear screening by the gas of phase solitons. DOI: 10.1134/S1063776119100017
1. INTRODUCTION: CDWS AND THEIR INTRINSIC DEFECTS 1.1. Theoretical and Experimental Motivations Charge density waves (CDWs) are ubiquitous in quasi one-dimensional (1D) electronic systems [1–3]. The CDW is a superstructure ∝ Aexp(q0r + ϕ) within the host crystal produced by spontaneous modulations of the electronic charge and atomic displacements. The CDW wave number q0 must be close to Fermi diameter 2kF of the parent metal thus opening a gap Δ ∝ |A| in the spectrum of electrons. We shall always keep in mind the most interesting and common case of incommensurate CDW which period π/kF is not a rational number of the atomic one when the periodicity of the underlying lattice does not play a role. Such a CDW possesses a manifold of degenerate states which energies do not depend on a sign of the amplitude A and on an arbitrary shift of the phase ϕ. The translational degeneracy of the CDW ground state leads to the phenomenon of Frolich conductivity showing up in a giant dielectric susceptibility, in a collective conductance by virtue of sliding and in many related nonlinear and nonstationary effects [1–3]. The degeneracy allows also for configurations connecting equivalent while different states across a disturbed area. These configurations are typically topologically protected or at least are protected by the
charge or spin conservation laws. They are known commonly under a generic name of “topological defects” which includes here extended objects like planes of domain walls as arrays of solitons [4, 5], lines or loops of dislocations [6–8] as phase vortices, and local objects like phase and amplitude solitons [4, 9, 10]. As well
Data Loading...
