SpinOrbit Scattering and EField Effects in Disordered Metals Near the MetalInsulator Transition
Abstract
The results of two studies of disordered metals near their metalinsulator transition are presented: (i) A detailed comparison of Ge(,x)Au(,1x) and B(,x)Cu(,1 x) is carried out in zero magnetic field. GeAu, a high Z material, has been shown to exhibit strong spinorbit effects in a magnetic field while BCu, a low Z material, has been shown to exhibit weak spinorbit effects. Both materials have similar temperature dependent dc conductivity behavior in zero field and approximately linear mobility edges; (ii) A detailed study of the nonlinear dc conductivity of GeAu and C(,x)Cu(,1x) is carried out for 1.3K < T < 4.2K and for Efields up to 500V/cm. Analyzing the (sigma)(E) data in the context of an electron gas heating model yields unphysically long electron relaxation times. Alternatively, the Efield can limit renormalization by raising the electron energy above the disordered potential. The system then changes from quantum mechanical scaling to classically diffusive behavior beyond a certain length scale. The temperature and Efield data can then give the characteristic lengths and prefactors for the transition.
 Publication:

Ph.D. Thesis
 Pub Date:
 1987
 Bibcode:
 1987PhDT........15O
 Keywords:

 AMORPHOUS CONDUCTORS;
 Physics: Condensed Matter