Electron-electron Interaction with Decreasing Conductance

The contribution of the electron-electron interaction to conductivity is analyzed step by step starting from the high conductivity in gated GaAs/InxGa1−xAs/GaAs heterostructures with different starting disorders. We demonstrate that the diffusion theory works down to kFl≃1.5−2, where kF is the Fermi quasimomentum and l is the mean free path. It is shown that the e–e interaction gives smaller contribution to the conductivity than the interference independent of the starting disorder, and its role rapidly decreases with decreasing kFl. © 2003 The American Physical Society.We thank Igor Gornyi for useful discussions. This work was supported in part by the RFBR through Grants No. 00-02-16215, No. 01-02-16441, and No. 01-02-17003, the INTAS through Grant No. 1B290, the Program University of Russia through Grants No. UR.06.01.002, and the CRDF through Grant No. REC-005