Temperature Dependence of the Inelastic Scattering Time in Metallic n-GaAs

抄録

Temperature dependence of the inelastic scattering time τ_ε in metallic n-GaAs (n=N_D−N_A=7.83×10¹⁶ cm⁻³) is determined experimentally in the wide temperature range of 50 mK–8 K by two methods: One is from the H² [H: magnetic field] dependence of the magnetoconductivity Δσ in weak fields, where Δσ=σ(H, T)−σ(0, T) is proportional to τ_ε^3⁄2H² [T: temperature]. The other is from the temperature dependence of Δσ in strong fields, which is given by Δσ=(e²⁄2π²h)[0.605(eH⁄ch)^1⁄2−(Dτ_ε)^−1⁄2], where D is the diffusion constant. We find that the two methods give the T⁻¹ temperature dependence of τ_ε. This result is in agreement with the recent theory of τ_ε∝T⁻¹ in 3-dimensional system calculated by Isawa.