Weak Localization in Bilayer Graphene: Enhanced Scattering near Dirac Point

The effects of quantum corrections on electron conductivity in bilayer graphene have been studied under various temperatures and gate voltages to seek the origin of the restrictions in electron conductions. Although previous studies suggested the enhanced intervalley scattering effect to be the major reason behind the restriction on electron transport, tested samples in this work exhibited the weak localization effect due to much weaker intervalley scattering rates. The enhancement of inelastic scattering near Dirac point are further tested to show the reason behind the inconsistency. It is successfully shown that the amount of electron-hole puddles, and thus, screening effects could enhance intervalley scattering near Dirac point.