Two-dimensional systems with Rashba spin-orbit coupling are not Galilean invariant and therefore electron--electron collisions in them may affect the current. However when taken alone, they cannot ensure a nonzero dc resistivity, so their effects are masked by impurity scattering. Here we calculate the related finite-frequency response and show that the electron--electron scattering in clean Rashba conductors decreases the Drude weight while resulting in a finite dissipative component of the response outside of the Drude peak.
The singular density of states and the two Fermi wavevectors resulting from a ring-shaped or "Mexican hat" valence band give rise to unique trends in the charged impurity scattering rates and charged impurity limited mobilities. Ring shaped valence bands are common features of many monolayer and few-layer two-dimensional materials including the III-VI materials GaS, GaSe, InS, and InSe. The wavevector dependence of the screening, calculated within the random phase approximation, is so strong that it is the dominant factor determining the overall trends of the scattering rates and mobilities wi…
We calculate the electrical and thermal conductivity of a two-dimensional electron gas with strong spin--orbit coupling in which the scattering is dominated by electron--electron collisions. Despite the apparent absence of Galilean invariance in the system, the two-particle scattering does not affect the electrical conductivity above the band-crossing point where both helicity bands are filled. Below the band-crossing point where one helicity band is empty, switching on the electron--electron scattering leads only to a limited decrease of the electrical conductivity, so that its high-temperatu…
Ionized Impurity and Surface Roughness Scattering Rates of Electrons in Semiconductor Structures with One-Dimensional Electron Gas and Broadened Energy Levels
Within linear-response theory we derive a response function that thoroughly takes into account the influence of elastic scattering and is valid beyond the long-wavelength limit. We apply the theo-ry to plasmons in graphene and the two-dimensional electron gas (2DEG), in the random-phase ap-proximation, and for the former take into account intraband and interband excitations. The scatte-ring-modified dispersion relation shows that below a critical scattering strength $γ_c$, simply related to the plasmon frequency $ω$, no plasmons are allowed. The critical strengths $γ_c$ and the allowed $(ω, q)…
Structure and coordinate dependence of the reflected wave, as well as boundary conditions for quasi-particles of graphene and the two dimensional electron gas in sheets with abrupt lattice edges are obtained and analyzed by the Green's function technique. In particular, the reflection wave function contains terms inversely proportional to the distance to the graphene lattice edge. The Dirac equation and the momentum dependence of the wave functions of the quasi-particles near the conical points are also found by the perturbation theory with degeneracy in terms of the Bloch functions taken at t…
The in-plane electron mobility has been calculated in InAs/GaSb type-II superlattices at low temperatures. The interface roughness scattering and ionized impurity scattering are investigated as the dominant scattering mechanisms in limiting the electron transport at low temperatures. For this purpose, the band structures and wave functions of electrons in such superlattices are calculated by solving the K.P Hamiltonian using the numerical Finite Difference method. The scattering rates have obtained for different temperatures and structural parameters. We show that the scattering rates are high…
