2011/04/26 by Richard L. J. Qiu, Xuan Gao, Xuan P. A. Gao +4 · 9 citations
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Charge-carrier density #Condensed matter physics #Degenerate energy levels #Doping #Electrical resistivity and conductivity #Materials science #Metal #Omega #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum mechanics #Sigma #Thermal conduction #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.83.193301
published in Physical Review B 83(19) (American Physical Society) · accepted for publication in Phys. Rev. B
arxiv created 2011/04/26 · openalex publication_date 2011/05/09 · arxiv updated 2015/05/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
It has been puzzling that the resistivity of high-mobility two-dimensional (2D) carrier systems in semiconductors with low carrier density often exhibits a large increase followed by a decrease when the temperature T is raised above a characteristic temperature comparable with the Fermi temperature TF. We find that the metallic 2D hole system in a GaAs quantum well has a linear density- (p-) dependent conductivity \ensuremathσ\ensuremath≈e\ensuremathμ*(p\ensuremath-p0) in both the degenerate (T\ensuremath≪TF) and semidegenerate (T~TF) regimes. The T dependence of \ensuremathσ(p) suggests that the metallic conduction d\ensuremathσ/dT<0 at low T is associated with the increase in \ensuremathμ*, the effective mobility of itinerant carriers. However, the resistivity decrease in the semidegenerate regime T>TF originates from the reduced p0, the density of immobile carriers in a two-phase picture.